Reconcile Singapore GST F5: Box 5 & Box 7 From AP Invoices

Reconciling a Singapore GST F5 from supplier invoices means gating each invoice through the input-tax conditions in sections 19 and 20 of the GST Act, classifying it into Box 5 (total taxable purchases, GST-exclusive) or Box 7 (input tax claimed), and tying the totals back to the accounting system. The special-case sub-flows that don't fit a clean box — import permits where Singapore Customs is the GST taxpayer rather than the supplier, simplified tax invoices priced as 9/109 of the inclusive total, the 12-month bad-debt repayment rule on invoices the buyer never paid — are part of the same close. Material errors on a return already filed are corrected by filing GST F7, not by silently adjusting the next period. The F5 itself is due one month after the end of the accounting period, and the question on every bookkeeper's desk in the run-up to that deadline is how to walk a quarter's supplier invoices into a filed return with working papers that hold up under an IRAS audit.

The corpus on a Singapore bookkeeper's desk in 2026 is hybrid. Local supplier PDFs sit alongside PINT-SG XML invoices arriving through the InvoiceNow stream as the mandate phases in, alongside Singapore Customs import permits, alongside simplified invoices for taxis and small-ticket spend, alongside foreign supplier bills that trigger reverse charge on Box 14 or Box 15. This guide walks the practitioner workflow that handles every one of those formats in a single F5 build, rather than treating each as a separate problem.

The arc the rest of the guide follows is the arc the quarterly close actually performs. Gate every invoice for input-tax-claim eligibility. Classify each surviving invoice into the right box. Walk the sub-flows where the maths is non-obvious: import permits, the 9/109 fraction, the 12-month rule. Consolidate a hybrid corpus into one working paper. Decide F7 versus next-F5 if anything material slipped. Archive the working papers in the shape an IRAS auditor expects to find. The Singapore quarterly GST close is a workflow, not a form-filling exercise, and that is the angle this guide takes.

The Input-Tax Eligibility Gate Every Invoice Has to Clear

Most explainers describe the input-tax conditions in a paragraph and then talk about Box 5 and Box 7 as though every invoice in the AP corpus belongs in them. The working assumption here is the opposite. Every invoice clears the gate first. Only invoices that clear are classified into a box. The few that fail are documented, not quietly dropped, because the working paper that survives an IRAS audit is the one that explains every excluded entry as cleanly as it explains every included one.

The gate is a six-condition checklist, drawn from sections 19 and 20 of the GST Act. Apply it to every invoice in the period:

The buyer is GST-registered at the time of the supply. If registration was effective only from a later date, no input-tax claim arises for invoices dated before that date. Failure mode: invoice excluded with a registration-effective-date note on the working paper.
The supply is for a business purpose and is not exempt. Personal expenditure run through the business account does not enter Box 7. Mixed business and private use is apportioned under the standard rules and only the business portion is claimed. Exempt supplies (financial services, residential property rental, certain investment metals) do not produce input GST and do not enter Box 5 either. Failure mode: invoice rejected from the F5 with the reason coded.
The buyer holds a valid tax invoice, simplified tax invoice (S$1,000 GST-inclusive or under), or Singapore Customs import permit. A delivery order, a payment receipt, or a quotation does not support a claim. Failure mode: invoice held pending fix. Email the supplier, get the proper document, and bring it into the next period's F5 if it lands after filing. For the full list of mandatory tax-invoice fields and the rules for simplified invoices, see Singapore GST tax invoice mandatory fields and simplified-invoice rules.
The recipient name on the invoice is the GST entity claiming. A sole proprietor's personal name on an invoice the company is trying to claim does not work. A trading name that differs from the registered legal name is fine if you can evidence the link, but evidence the link in writing on the working paper. Failure mode: invoice flagged for buyer-side action — usually a corrected invoice from the supplier, occasionally a same-name memo for a known-good mismatch.
The claim is within the five-year statute. Input GST cannot be claimed on supplies more than five years old. Failure mode: claim time-barred. Document the reason and exclude.
The supplier is GST-registered. Cross-check the supplier's GST registration number against the IRAS GST register at the point of receiving the invoice, not at the point of filing. This is the buyer's discipline against missing trader fraud and against accidentally claiming on an invoice the supplier is not entitled to issue. Failure mode: claim withheld; investigate the supplier before paying the invoice.

The output of the gate is a single artefact: a gated AP list for the period, where every invoice carries a status of approved-for-classification, held-pending-fix, or excluded-with-reason. The classification work in the rest of the close runs against the approved slice. The held and excluded entries stay on the list — they are part of the working paper, not silent gaps in it.

Classifying Approved Invoices Into Box 5, Box 7, and the Sibling Boxes

Box 5 carries the GST-exclusive value of the period's total taxable purchases. Box 7 carries the total input tax claimed. Build each box as a sum of distinguishable categories rather than a single number — the practitioner discipline is sub-totals tied back to specific queries against the AP system, because that is what makes the F5 reconcilable rather than asserted.

Box 5 sub-totals to build:

Standard-rated supplier invoices, GST-exclusive value. The largest category in most AP corpora.
Zero-rated taxable purchases, where the supply is taxable but charged at 0% — international services, exports of goods that the buyer paid for inbound, and similar.
Imports of goods. Box 5 takes the supplier-invoice taxable-purchase value here; the corresponding GST flows through Box 7 from the import permit, not from the supplier invoice. The mismatch maths sits in the next section.
Simplified-invoice purchases. Box 5 takes the GST-exclusive component derived from the inclusive total using the 9/109 fraction. The derivation sits two sections on.
Reverse-charge taxable purchases on imported services and Low-Value Goods. These hit Box 5 as well as Box 14 or Box 15.

Exempt purchases do not enter Box 5. Salaries, dividends paid, and similar non-supplies do not enter Box 5. Get this discrimination right at coding rather than at the box build, or the AP-system reconciliation will not tie.

Box 7 sub-totals to build:

Input GST on standard-rated supplier invoices.
Input GST on import permits — sourced from the permit, not the supplier invoice.
Input GST derived from simplified invoices using the 9/109 tax fraction.
Input GST claimable under reverse charge for the Box 14 and Box 15 entries, where the buyer is entitled to recover. Not every reverse-charge entry produces a recoverable claim — partial-exemption businesses recover only the attributable proportion.
Input GST on customer-accounting-for-prescribed-goods purchases, where the buyer self-accounts for the output tax in Box 6 and claims the matching input tax in Box 7 subject to the same conditions as any other claim. The per-invoice mechanics for the buyer side live in buyer-side customer accounting for prescribed goods on Box 6 and Box 7; on the F5 build, the bookkeeper sums the buyer-side CAPG entries into Box 6 and Box 7 and ties the totals back to the AP system.

The reverse-charge boxes (Box 14, Box 15). Box 14 carries imported services subject to reverse charge; Box 15 carries Low-Value Goods imports under the overseas vendor regime that the buyer self-accounts for. The per-invoice reverse-charge mechanics — when the rule applies, what the entries look like, how partial-exemption businesses handle the claim — are a workflow in their own right and out of scope here; for the Box 14 side specifically, the reverse-charge GST workflow on foreign supplier invoices walks the RC Business gate, the OVR-versus-RC test, and the partial-exemption cash impact. On the F5 build, the bookkeeper sums the RC-bearing entries into Box 14 and Box 15 as taxable values, and brings the corresponding input tax (where claimable) into Box 7.

The disallowed-input-tax categories drop out of Box 7. Motor cars, with the documented exceptions for goods vehicles, taxis used in a passenger-transport business, and the rest of the Reg 26 list. Club fees, family benefits, and employee medical expenses (with the post-pandemic statutory medical exceptions) under Reg 27. The working paper carries the disallowed list as a reconciliation item: invoices coded with GST that legitimately do not end up in Box 7. An auditor wants to see those entries identified, not absent.

The discipline at the end of this step is one query per sub-total. For each Box 5 and each Box 7 sub-total, the working paper records the AP-system query that produced the figure, the figure itself, and the source slice it ran against. The next four sections walk the sub-flows where the figure on the working paper does not come from a single straight query.

Import Permit Reconciliation When Permit Value Differs From Invoice Value

On imports of goods, the GST is paid to Singapore Customs at the point of import, not to the supplier. The supplier invoice carries the goods value (and may include the supplier's own freight, insurance, or other charges agreed in the commercial terms). The Customs import permit, lodged through TradeNet, carries the value Customs assessed under the CIF + duty + other charges base and the GST that was paid against it. For the F5, Box 5 reflects the supplier-invoice taxable-purchase value because that is the supply you bought; Box 7 reflects the GST shown on the import permit because that is the GST you actually paid.

In practice the two values rarely match precisely, and the reconciliation note is what holds the entry together at audit.

Worked example. An overseas supplier ships you a consignment of goods on commercial-invoice terms of S$10,000 plus inbound freight of S$500, for a supplier-invoice total of S$10,500. Singapore Customs assesses the same consignment on a CIF + duty + other-charges basis, and the import permit shows GST charged on a Customs Value of S$11,200, producing GST at 9% of S$1,008. The F5 entries land as follows:

Box 5: the supplier-invoice taxable-purchase value. Whether the S$500 of inbound freight is included in Box 5 depends on whether it formed part of the taxable supply from the supplier (single combined supply of goods including freight, in which case Box 5 = S$10,500) or a separate transport service from a different party (in which case the freight is treated separately on its own merits). The practitioner test is the supplier's invoice and the underlying contract, not the gross figure on the permit.
Box 7: S$1,008 — the GST on the permit, taken verbatim. Do not derive Box 7 from 9% of the supplier-invoice value, because that is not the GST that was paid.

The working paper carries a one-line reconciliation note against the entry: "Box 5 = supplier invoice value (with freight treatment described); Box 7 = import permit GST," with both figures cited and the permit number recorded. An auditor reading the period file does not have to reverse-engineer the mismatch.

When the permit is not in hand at quarter-end. If a permit has not yet been issued, has been queried by Customs, or is in the process of correction, hold the input GST claim until the permit is in hand. Do not estimate the GST from the supplier invoice value. Do not claim the supplier-invoice GST line — there is no supplier-invoice GST line on goods imports, because the supplier did not charge Singapore GST. The held entry rolls into the next period when the permit lands. Note the held status on the gated AP list so the entry is not lost.

For each import in the period, the working paper retains: the supplier invoice, the Customs permit (with the permit number searchable in TradeNet for five years), shipping documents where they form part of the value chain, and the reconciliation note that ties the supplier-invoice side to the permit side. Read together, those four artefacts answer every reasonable audit question about the entry without a phone call back to the bookkeeper.

Simplified Tax Invoices and the 9/109 Input-Tax Derivation

A simplified tax invoice is permitted for supplies of S$1,000 or under (GST-inclusive). The simplified format does not break out GST as a separate line — it shows a total inclusive figure, sometimes with a "Price includes GST" notation, sometimes without. To bring the entry into Box 7, the buyer derives the input GST from the inclusive total using the 9/109 tax fraction. The fraction is the GST rate over one plus the GST rate, expressed as a percentage of 100: 9 / (100 + 9) = 9/109.

Worked example. A taxi receipt for S$54.50 GST-inclusive:

Input GST = 54.50 × 9 / 109 = S$4.50 (Box 7 entry)
GST-exclusive value = 54.50 − 4.50 = S$50.00 (Box 5 entry)

The working paper records all four figures against the entry: the inclusive total, the 9/109 derivation written out, the resulting GST, and the resulting GST-exclusive value. Source-document reference cites the receipt number, supplier name, and date. An IRAS auditor following the maths from the working paper to the F5 sub-totals does not need to re-derive anything from the accounting system — the derivation is on the page.

The threshold edge matters. At S$1,001 GST-inclusive or higher, a simplified invoice does not support an input-tax claim. The buyer needs a full tax invoice with GST shown separately. If a supplier issues a simplified-format document for a higher-value supply, the entry sits in held-pending-fix on the gated AP list until the supplier provides a full tax invoice. Estimating GST from a non-compliant document and claiming the result is not a recognised position.

The retention discipline. Simplified invoices arrive as short receipts, frequently photographed on a phone or printed on thermal paper that fades within months. The working paper retains the simplified invoice itself — preferably as a clean scan or a structured digital capture — for the same five-year retention period that applies to full tax invoices. Faded thermal paper without a scan on file is, at audit, no document at all.

The 9/109 path adds up across a quarter. A bookkeeper handling fifty taxi receipts and a hundred small-supply purchases is reconciling Box 5 and Box 7 against figures that came from a derivation, not from a GST line on the supplier's invoice, and the working-paper annotation is what makes that defensible.

The 12-Month Bad-Debt Rule and the Box 7 Reversal Entry

Section 19(12) of the Singapore GST Act requires a taxable person to repay to the Comptroller any input tax claimed on a supplier invoice that has not been paid to the supplier within 12 months of the due date of payment. The rule is set out in the IRAS e-Tax Guide on preparing the GST return. It is mechanical: the clock starts at the due date on the invoice (not the invoice date), and an unpaid invoice that crosses the 12-month mark requires a repayment in the F5 of the period in which the mark was crossed, regardless of why the invoice is unpaid.

This is one of the most-missed entries in Singapore quarterly close, and it is one of the first things an IRAS auditor cross-checks against the AP aging report. Build the check into the period close so it never depends on memory.

The quarter-end procedure. Run the AP aging report at the period-close date. Filter for invoices where input GST was claimed in a prior period and the due date is more than 12 months before the period-close date, with the invoice still partly or wholly unpaid. Each surviving entry triggers a Box 7 reversal in the current period.

Worked example. A supplier invoice of S$5,450 GST-inclusive (S$5,000 net to Box 5 in the original period; S$450 GST claimed in Box 7) was due 13 months ago and remains unpaid at the current quarter-end. The current-period F5 carries a Box 7 reversal of S$450. On the working paper, the entry shows up as a discrete line:

Sec 19(12) repayment — invoice [number] — supplier [name] — due [date] — claimed [original period] — repaying S$450

Box 5 is not reversed. The taxable purchase happened; the supplier was entitled to issue the invoice; only the input-tax claim is unwound until payment occurs.

The re-claim entry. If the buyer later pays the supplier — in full or in part — the corresponding input GST is re-claimed in the F5 of the period of payment. The working paper for that later period carries the matching line:

Sec 19(12) re-claim — invoice [number] — paid [date] — re-claiming S$450

Both entries live in the audit trail. An auditor walking the supplier ledger from invoice through original claim through repayment through eventual re-claim sees a continuous record, not a missing entry that has to be explained from memory.

Partial payment and ongoing dispute. Partial payment within the 12 months allows the buyer to keep the proportion of input GST that maps to the paid portion; only the input GST attributable to the unpaid portion is repaid at the 12-month mark, and re-claimed if and when the rest is paid. Ongoing dispute does not pause the 12-month clock — the rule runs against the due date regardless, and a dispute that drags past 12 months still triggers repayment in the period the mark was crossed. The audit-defensible position is to repay on time and re-claim on settlement, not to delay repayment because resolution is supposedly close.

The artefact this section produces is a section-19(12) reconciliation list that the bookkeeper builds every quarter, derived from the AP aging report and the prior periods' working papers. The list shows every invoice currently subject to repayment, every invoice repaid this period, and every invoice re-claimed this period. Filed alongside the F5 working paper, it answers every reasonable 12-month-rule question without further investigation.

Consolidating a Hybrid PDF and PINT-SG Corpus Into One F5

The Singapore InvoiceNow mandate phases in through 2031, and for the foreseeable future every Singapore bookkeeper's AP corpus is hybrid. Some suppliers send PINT-SG XML invoices through the Peppol network; many still issue PDFs; a few mix the two within the same supplier relationship while their billing systems migrate. Pretending the rollout is complete and treating PINT-SG as the only inbound format misleads the close. Pretending PDF is the only format misses the XMLs that are already arriving. Build the workflow for both. The deeper context on which suppliers fall under which phase, and what the cut-overs actually require, is in Singapore InvoiceNow PINT-SG mandate and rollout timeline.

The trick is that the F5 working paper does not care what format the source invoice arrived in. It cares about a row shape, and that row shape is the same regardless of source:

Invoice number
Invoice date and due date
Supplier name and UEN
Supplier GST registration number (cross-checked against the IRAS register at the gate)
Recipient name (the GST entity claiming)
GST-exclusive amount (Box 5 contribution)
GST amount (Box 7 contribution)
Document type (tax invoice, simplified invoice, import permit, RC entry)
Eligibility-gate result (approved / held / excluded with reason)
Source-document reference for audit traceability

For PINT-SG XML invoices, those fields are already structured. The XML follows the UBL schema with the PINT-SG customisation, and a parser pulls each field directly. The mechanical conversion of PINT-SG XML into row-level data the working paper consumes is its own workflow, walked in convert PINT-SG XML invoices into Excel working-paper rows.

For PDF invoices — local supplier PDFs, foreign supplier bills, simplified taxi receipts, scanned import permits — the same row has historically been built by manual data entry. That is the half of the hybrid corpus that consumes the bookkeeper's quarterly hours, and where automating the field extraction collapses days of typing into a structured output the working paper can consume directly. AI invoice data extraction for Singapore AP handles the PDF half: feed the period's supplier PDFs in as a batch, describe the row shape needed in a single natural-language prompt the bookkeeper writes once and re-uses every quarter, and the output is an Excel or CSV file with one row per invoice that drops alongside the parsed PINT-SG rows in the same working-paper sheet.

The discipline is one row shape, two ingestion paths, one working paper. The eligibility gate runs against the merged set. The Box 5 and Box 7 sub-totals tie back to AP-system queries that draw from the same coded transactions regardless of how the underlying document arrived. What an IRAS auditor sees at audit is the working paper, not the inbound formats — and that is the point.

When to File a GST F7 Versus Roll an Error Into the Next F5

Errors discovered after a return is filed do not rewrite history quietly. IRAS sets a materiality threshold for when a correction must be filed as a GST F7, and when it can be netted into the next F5 instead. The threshold is the larger of S$1,500 net GST (the absolute floor) and 5% of the original GST amounts on the affected return. An error breaching either limb requires F7. An error below both limbs can be adjusted in the next F5 by netting the correction into the relevant box.

The decision tree the bookkeeper applies:

Identify the error and quantify its GST impact on the period it affects. The impact is the change in net GST that would have resulted had the error not been made — which usually means a Box 7 over- or under-claim, or a Box 5 mis-classification that flowed through to Box 7.
Compare against the threshold. Above S$1,500 net GST or above 5% of the original GST amounts on that return, file F7. Below both, roll forward.
For roll-forwards, net the correction into the next F5's relevant box and record the correction note on the working paper:

Period [Q] correction — invoice [number] — supplier [name] — net GST adjustment S$[x] — reason: [coded ineligible / late permit / classification / missed sec 19(12) / etc.]

Common error patterns at quarter-end. Build the period close to look for these explicitly, because most of them surface only when someone goes looking:

Input GST claimed on an invoice later found ineligible. A supplier turned out not to be GST-registered, the invoice was issued in the wrong recipient name, the supply was mixed-use and not properly apportioned. Box 7 reduces.
Input GST under-claimed because a permit landed late. The import happened in the prior period but the Customs permit was issued or corrected after the F5 had been filed. Box 7 increases.
Classification errors between standard-rated and zero-rated, or between Box 5 and exempt. Usually surfaced by the AP-system reconciliation, not by the bookkeeper's memory.
A missed section 19(12) entry from the prior period. An invoice that crossed the 12-month mark but was not picked up on the prior aging report. Box 7 reverses in the period the rule applied, not the period of discovery — file F7 if the impact crosses the threshold.

The F7 mechanic. F7 is filed via myTax Portal. The form lists each error against the period it affects, with the corrected box values and the resulting net-GST change. Once accepted by IRAS, the corrected F5 supersedes the original; the working paper for the original period is updated with the F7 reference and the corrected box values, and the next period's working paper records that the F7 was filed and the prior period closed.

Voluntary disclosure is the practitioner-defensible position. IRAS encourages voluntary disclosure of errors and may reduce or waive penalties when disclosure is timely and unprompted. Discovering an error at the next quarter-close and filing F7 in the same week reads, at audit, very differently from an error IRAS surfaced first. The decision tree always favours the F7 over silently absorbing the entry.

The Working-Paper Archive That Survives an IRAS Audit

IRAS describes record-keeping rules in the abstract: keep the underlying records for five years, retain enough to support the figures filed. What the rules do not describe is the practical archive shape — what the period file actually contains, how it is organised, and what an auditor lands on when handed it. That is where most band-2 explainers stop and where the practitioner-workflow gap lives, so this section is where the article earns its audit-defence promise.

The artefacts the period file carries:

The signed-off F5 working paper itself. The box-by-box build, the sub-totals, the queries that produced each sub-total, and the ties back to the AP system. This is the document an auditor opens first.
The gated AP list from the eligibility-gate step. Every invoice in the period with its status: approved-for-classification, held-pending-fix, or excluded-with-reason. The held and excluded entries are part of the audit trail, not gaps in it.
The supporting invoice store. Every PDF supplier invoice, every simplified-invoice scan, every PINT-SG XML in its native form alongside a human-readable rendered version, every Singapore Customs import permit referenced in the working paper. Organised by period and by supplier, with the source-document reference on each working-paper row pointing to a specific file.
The section 19(12) reconciliation list. The 12-month entries reversed in the period, the entries re-claimed in the period on subsequent payment, and the open list carried forward.
The accounting-system reconciliation. The queries and figures that tie each Box 5 and each Box 7 sub-total to the AP system, plus the explicit reconciliation of timing differences, classification differences, and the disallowed-input-tax categories that legitimately do not flow into Box 7.
Any F7 corrections that touched the period. The F7 working paper, the corrected box values, and the cross-references in both directions — the original period's working paper updated with the F7 reference, and the F7 filing pointing back to the original period.
Controls evidence. The supplier-UEN checks, the supplier-GST-registration checks against the IRAS register, the recipient-name checks, and the higher-risk supplier due-diligence steps the bookkeeper performed before paying. For the practitioner checklist that produces this evidence, see the Missing Trader Fraud due-diligence checklist for Singapore AP.

Retention rule. The underlying records are kept for five years from the end of the relevant accounting period. The working paper itself is retained as a snapshot of what was filed, even if the accounting system that generated it has since been updated, restated, or migrated. A live report regenerated three years later from updated transaction data is not the same as the working paper that supported the original F5 — keep the snapshot.

Format and storage, pragmatically. The archive can live in cloud storage organised by period folder, in the accounting system if it supports immutable period locks, or in a structured file share. The format choice is secondary; what matters is that an IRAS auditor can be handed the period file and find every artefact named above. PDFs and Excel are the practical formats for the working paper itself, with the PINT-SG XMLs retained in their native machine-readable form alongside human-readable rendered copies — the XML is the legal record, the rendered copy is the readable record.

The audit-defence test. An IRAS auditor lands on the period file and, within an hour, can:

Read the box-by-box F5 build with sub-totals.
Trace any sub-total to the AP-system query that produced it and to the supporting invoices behind that query.
See the eligibility-gate decision for any invoice in the period — including the held and excluded entries, with their reasons.
Read the 12-month rule reconciliation and reconcile every Box 7 reversal and re-claim.
See any F7 correction that touched the period and reconcile the corrected figures against the original.
See the controls evidence behind the higher-risk entries.

If the auditor can do all six in an hour, the working paper has done its job. If any of them requires a phone call back to the bookkeeper or a re-run from the accounting system, the working paper has not.

Practitioner Workflow in Xero, MYOB, and the Excel Fallback

The article's workflow is software-independent, but the workstation matters because it shapes what the bookkeeper has to do manually and what the system handles. Xero and MYOB both generate F5 reports from coded transactions; the discipline is to code consistently throughout the period so the GST F5 report is a clean output of what was already true, not a reconstruction at quarter-end. Excel is the fallback for clients on legacy software, hybrid corpora that no single accounting system fully captures, or external accountants consolidating multiple clients' figures into one set of working papers.

Xero. Code AP transactions with the right GST tax rate as you go: standard 9%, zero-rated, exempt, the imported-services and Low-Value-Goods reverse-charge codes for Box 14 and Box 15 entries, and the simplified-invoice handling so the GST-exclusive split lands in Box 5 correctly. At quarter-end, run the GST F5 report. Reconcile the report figures against the AP aging report and the prior-period F5 working paper. Handle the special-case sub-flows manually, because Xero's standard F5 report does not auto-generate them: the section 19(12) repayments and re-claims, the import-permit reconciliations where the supplier-invoice value differs from the permit value, and any F7 corrections that touched the period. Feed the reviewed Box 5 / Box 7 figures into myTax Portal — the report generates the numbers; you are responsible for them.

MYOB. The workflow shape is the same. Code consistently, run the MYOB GST report at quarter-end, reconcile against the AP aging and prior-period working papers, handle the sub-flows manually, file via myTax Portal. The mechanics differ in detail — different tax-rate codes, different report format, different conventions for the disallowed-input-tax categories — but the discipline is identical: the system gives you a starting figure, the bookkeeper makes it audit-defensible.

Inbound PINT-SG into the AP ledger. Both Xero and QuickBooks support receiving PINT-SG Peppol invoices directly into the AP ledger, so the operational integration that feeds F5 prep does not depend on manual data entry from the XML. The setup mechanics — connecting the Peppol Access Point, mapping suppliers, handling the routing identifiers — sit in receive Singapore InvoiceNow Peppol invoices into Xero or QuickBooks. With that integration in place, the bookkeeper's quarterly close starts from coded AP entries rather than from a folder of XMLs awaiting parsing.

The Excel fallback. When the accounting system does not produce a clean F5 report, or when the client's data lives across multiple systems, the working paper is built directly in Excel. The sheet structure is one row per invoice using the row shape from the previous section: invoice number, date, supplier name and UEN, supplier GST registration number, recipient name, Box 5 amount, Box 7 amount, document type, eligibility-gate result, and source-document reference. Sub-total queries by box and category sit at the foot of each section: standard-rated total, zero-rated total, import-permit GST total, simplified-invoice 9/109 total, RC total, disallowed-input-tax total. The F5 box build sits at the bottom referencing the sub-total queries — Box 5 = sum of the relevant sub-totals; Box 7 = sum of the relevant input-tax sub-totals; Box 14 and Box 15 from the RC entries; net GST per the F5 form. Filed alongside the supporting invoice store and the controls evidence, the Excel working paper is as audit-defensible as the system-generated equivalent.