Process a UK Plant-Hire Invoice (CPA Terms) for Construction AP

A weekly plant-hire invoice from Sunbelt Rentals, Speedy, or GAP Hire Solutions arrives in the AP inbox on a Monday. Before it posts and goes to payment, every line on it has to be checked against the hire contract that produced it. That contract, on almost every UK plant hire of any size, is the CPA Model Conditions — and to process a UK plant hire invoice properly, the AP team has to read each line in the language of those conditions.

The verification job is a six-line checklist:

• On-hire and off-hire dates match the hirer's on-hire ticket and the supplier's off-hire confirmation.
• The hire-period calculation charges the right number of weekly hire-rate periods, with partial weeks at the start and end correctly prorated.
• Idle time is charged at the contract idle rate — by CPA convention, two-thirds of the working hire rate — not the full rate.
• Breakdown days during which the plant was unusable through mechanical failure are not charged.
• Dilapidation lines are supported by on-hire and off-hire condition records and an itemised repair quote.
• The VAT treatment is correct line by line: plant-only hire is standard-rated as goods, plant-with-operator is reverse-charged as construction services.

The contract framework comes from the Construction Plant-hire Association (CPA), the UK trade body for plant owners. The Construction Plant-hire Association publishes the CPA Model Conditions 2021 as the standard business-to-business hire contract framework used across UK plant hire, with separate condition sets for plant-only hire, plant-with-operator and Contract Lifting Services, and supplementary conditions for tower cranes, hoists, concrete pumps, mobile and crawler cranes, MEWPs, tools and shoring. Most major hirers issue their own customer terms that republish or lightly adapt these conditions, so when the article refers to "the contract" it usually means the supplier's republished CPA conditions plus any negotiated variations.

The CPA terminology the rest of the article uses is worth fixing now. The hirer is the contractor's side — the AP team's employer, taking plant on hire. The owner is the supplier issuing the invoice. On-hire and off-hire are the events that bound the chargeable period: on-hire when the plant arrives on site, off-hire when the supplier collects it back. The hire period is the chargeable period itself, measured in hire weeks. Idle time is the chargeable period during which the plant cannot be used. Dilapidation is damage on return that exceeds fair wear and tear.

The rest of this article walks the invoice line by line: on-hire and off-hire dates and the chargeable hire period, the idle-time rate, breakdown chargeability, dilapidation evidence, the plant-only versus plant-with-operator VAT split (and its scaffold parallel), sub-hire pass-through on a subcontractor invoice, and the supplier-master and recurring-cadence design that holds the whole control together.

On-hire, off-hire, and the chargeable hire period

The meter starts the moment the plant lands on site. Whatever the supplier calls it — on-hire ticket, on-hire form, on-hire confirmation, delivery note — that timestamped record is the documentary start of the chargeable period, and the invoice's start date has to match it. Sunbelt and Speedy both run app-based on-hire confirmations through the driver's tablet at delivery; GAP and the smaller hirers tend to leave a paper delivery note. Either way, the date and time stamp on that record is what AP compares the invoice's first hire week against.

Stopping the meter is harder than starting it, and this is where most hire-period disputes live. CPA convention requires the hirer to off-hire formally — in writing, dated, naming the kit and the site — and to obtain a corresponding off-hire reference number from the supplier. A phone call to the depot does not stop the meter. An email to the supplier with no acknowledgement does not stop it on its own either. Until the supplier confirms off-hire and issues the reference, the hire continues to charge, weekends and bank holidays included, even with the plant sitting unused at the gate. Sunbelt's customer portal, Speedy's account portal, and GAP's online account each produce a logged off-hire request with a reference number out the other side; that is the cleanest evidence chain.

Once the start and end are fixed, the hire-period calculation falls out of them. The contract weekly rate covers a defined hire week — usually seven calendar days from on-hire — and partial weeks at either end are charged under the supplier's standard conditions, typically as a daily rate that prorates against the weekly rate but caps at it. The recurring rounding error sits in those partial weeks. AP verifies the day count from on-hire to the first week boundary, and from the last week boundary to off-hire, against the on-hire ticket and the off-hire confirmation. A common pattern is for the supplier to charge a full week at one end against five working days that the kit was actually on site; whether that is contractually correct depends on the conditions, but AP at least has to spot it.

Take the typical off-hire dispute: the plant manager believes off-hire happened on Friday afternoon when the kit was loaded onto the supplier's lorry; the invoice charges through to the following Tuesday. AP escalates with the on-hire ticket, the dated off-hire request from the named site contact, and any portal confirmation reference; the supplier produces the driver's collection record and a depot booking-in time. Be honest about where these settle. Most off-hire disputes resolve at one or two days of hire credited rather than the full disputed period, because under CPA the burden of formal off-hire sits with the hirer, and a Friday-afternoon load followed by a Tuesday booking-in often means the supplier has a defensible reason for charging the weekend.

A defensible audit trail for an AP team running this control at scale has four elements: the on-hire ticket with date and time stamp on file; a dated off-hire request from a named site contact rather than a generic site email; the supplier's off-hire reference number; and, where the plant manager runs condition photography as standard, the off-hire photographs in the same folder. With those four on file, an off-hire date dispute starts from a strong position; without them, AP is arguing without evidence and the credit is not coming. A known shutdown — Christmas, a long bank holiday weekend — has to be off-hired before it begins, not during, since the meter does not pause for the calendar.

Idle time at the contract idle rate

Idle time on a CPA hire is the chargeable period during which the hirer cannot use the plant for a reason that is not the supplier's responsibility — weather days, site closures, contractor delay holding up the work front, possessions running over on rail jobs. Practitioners sometimes call it waiting time or standing time; on the invoice it appears as a dedicated line or as flagged days within the hire period.

The rate convention under the CPA Plant Only and Plant with Operator Model Conditions is that idle time is chargeable at the contract idle rate, set by CPA convention at two-thirds of the working hire rate. Most major hirers republish that two-thirds figure verbatim in their customer terms; some — typically the smaller and the more bespoke hirers — apply a different fraction or charge full rate for short idle periods.

The spot-check is mechanical. Compare the rate per idle day on the invoice against the rate per working day on the same hire. Equality is the signal. A telehandler hired at £300 per working day that is also charged at £300 for an idle day on a CPA-conformant contract is not correctly billed; the idle day should be at £200. The same test runs against the weekly rate where idle days are charged as fractions of a week.

Challenging the line is straightforward where the contract follows CPA. AP requests a credit, citing the idle-time clause in the supplier's published conditions and naming the relevant condition set (Plant Only or Plant with Operator). The supporting evidence is the daily plant return showing the idle days; without the plant manager's record, AP cannot assert which days were idle in the first place, so the daily return is doing as much work as the clause cite. Credits at this point are usually agreed without much friction.

Where the supplier's conditions genuinely vary from CPA two-thirds — they charge full rate, apply a different fraction, or require advance notification of idle periods that wasn't given — this is no longer an AP fix but a procurement or project QS issue: escalate with the contract reference rather than argue about a clause that was never agreed. Where AP keeps catching the same supplier for the same variance, that is a flag for the next contract negotiation rather than a recurring battle on every weekly invoice.

Breakdown days and what should not be charged

Under the CPA Plant Only and Plant with Operator Model Conditions, breakdown risk is allocated to the owner. Where a mechanical breakdown of the plant prevents its use, hire is not charged for the period the plant is unavailable. Some suppliers' republished conditions carry that position verbatim; others apply a minimum-period threshold — no credit for breakdowns under a working day, for example — which is a contractual variance the AP team has to know about for each supplier on the hire ledger.

The answer differs by cause, and the cause typology is what AP works through:

• Mechanical breakdown of the plant itself. Credit due under CPA. The supplier's responsibility, the supplier's risk; AP requests a credit for the unavailable period.
• Operator misuse. Where the plant came with operator and the operator caused the failure, or where the hirer's own operator damaged plant-only hire, the line is chargeable. AP is not requesting a credit; the supplier may also be raising a separate dilapidation recharge.
• Running out of fuel. Operator and hirer responsibility, chargeable. The kit is technically working; the on-site cause is the hirer's.
• Weather damage. Case by case. Storm damage to a tracked excavator parked correctly is one conversation; flooding because the site management plan failed to relocate the plant is another. The contract usually allocates this through a force majeure or site-conditions clause rather than under breakdown.

The evidence pack is what makes a breakdown credit defensible. The plant manager records the downtime in the daily plant return, captures the cause as reported by the operator or the supplier's call-out engineer, and retains the engineer's report or job sheet from the visit. AP cites the daily return and the engineer's report when requesting the credit. Without the engineer's report, the cause is contested and the credit is harder to land.

Mechanical breakdowns supported by a clean engineer's report settle without much friction. Where the cause is in dispute — the supplier reads it as operator misuse, the plant manager reads it as a mechanical fault — the realistic outcome is a partial credit or a negotiated reduction of any dilapidation recharge that follows. Settlement happens on the documentation rather than on the principle.

Plant with Operator brings a wrinkle worth flagging. Under that condition set, the operator is the supplier's employee, so operator-side cause is the supplier's risk and the line between operator error and mechanical fault is the supplier's to defend. AP's job is to log the downtime through the daily return and escalate; adjudicating whether the operator stalled the kit or whether the kit stalled itself is not a control AP can run.

Dilapidation charges and the on-hire condition record

Dilapidation under CPA is the chargeable difference in condition between on-hire and off-hire where damage exceeds fair wear and tear. It is a separate charge from the hire itself and usually appears either as its own line on the final hire invoice or as a follow-up dilapidation invoice issued once the supplier has inspected the returned plant at the depot.

The documentation chain on the supplier's side has three anchors: the on-hire condition record (photographs, a signed condition form, or both, taken at delivery), the off-hire condition record (photographs at collection or at the depot, with whatever annotation the supplier's process produces), and the supplier's repair quote or repair invoice as the basis for the cost. CPA convention puts the burden on the owner to evidence both the difference in condition and the cost of putting it right.

That gives the AP team a clear default position. Where any of the three anchors is missing, AP refuses the line and asks for the evidence. No on-hire condition record means no baseline for the comparison. No off-hire photographs mean no evidence of the damage at the point of return. No itemised repair quote means no evidence of the cost. Until the chain is complete, the line does not pay.

In practice, the documentation is rarely complete on both sides — on-hire records taken in poor light or at the gate without a walk-around, off-hire records sometimes taken at the depot rather than at the hirer's site (raising legitimate questions about transit damage), repair quotes given as list prices rather than itemised parts and labour. A dilapidation charge plant hire dispute is rarely a clean argument; where evidence is partial on both sides, the realistic outcome is a negotiated reduction rather than a full credit or full payment. Where the on-hire record is genuinely strong (timestamped photographs of the kit on arrival, a signed condition form with the operator's notes), AP has the leverage to refuse the line outright until matching off-hire evidence is produced at the same standard.

Without on-hire and off-hire condition photography running as a standard plant-manager control, the AP challenge collapses to paying what is billed — a control-design issue for the project QS or operations lead, not something AP can fix at the invoice review stage.

Plant-only versus plant-with-operator: the VAT split on a single hire invoice

Plant-only hire — plant supplied without an operator — is a supply of goods on hire, standard-rated for VAT and outside the construction-services definition that triggers the domestic reverse charge. The supplier charges VAT at 20%; the hirer recovers it through the VAT return as normal. Plant-with-operator hire is a supply of construction services. Where the supply is to a non-end-user, VAT-registered customer in the construction industry, DRC applies: the supplier issues a DRC-compliant invoice with no VAT charged, and the hirer accounts for the VAT under the reverse charge.

That split is the spine. The framework underneath it (when DRC applies, the end-user notification rule, the CIS interaction) sits at the domestic reverse charge mechanics for UK construction services — this section walks the plant-hire-specific application rather than re-explaining the underlying rule.

Scaffold cuts the same way. Scaffold hire — the structure rented without erection labour, just the components on site — is goods on hire, standard-rated. Scaffold erection and dismantling labour is construction services, DRC applies. A single scaffold supplier's invoice frequently carries both: an "erect and dismantle" labour line under DRC plus a "scaffold hire" line under standard VAT. The treatments differ by line, not by invoice header.

The same line-by-line discipline applies to plant. A single weekly hire invoice can mix DRC and standard-rated lines without contradiction. A telehandler on plant-only hire (no operator, standard) plus a separate line for an operator-driven crane lift on the same site (DRC) on the same supplier's weekly invoice is a real configuration. AP has to read each line for the operator status before applying the VAT code, not look at the supplier or the invoice header and stamp the whole document one way.

Three supplier mis-coding scenarios are worth catching:

• DRC applied to plant-only hire. Incorrect, because the supply is goods. The hirer should not be reverse-charging; the supplier should be charging VAT at standard rate. AP rejects the invoice and asks for a re-issue with VAT applied. The hirer cannot just self-correct by accounting for the VAT — the supplier's invoice has to be right for the VAT recovery to stand.
• Standard rate applied to plant-with-operator hire when the customer is a VAT-registered, non-end-user contractor in construction. Incorrect; DRC applies. AP rejects and asks for a DRC-compliant re-issue with no VAT charged.
• End-user status not notified. Where the hirer is genuinely an end user — a developer running its own works rather than a contractor in the chain — DRC does not apply on plant-with-operator. But the end-user status only takes effect once the customer has notified the supplier in writing; absent that notification, the supplier defaults to applying DRC, and the supplier is right to do so. The fix is the notification, not an invoice rejection.

The CIS overlay sits on plant-with-operator. Where the operator is paid by the supplier as labour and the supplier is CIS-registered, the operator-labour element falls within CIS, and the supplier should appear on the contractor's CIS verification list before the invoice pays. The link above covers the CIS and DRC interaction; the practical AP point is that a plant-with-operator hire from a labour-supplying CIS-registered supplier needs both the DRC treatment and the CIS verification done — one without the other leaves an open exposure.

A note on contract lifting because some practitioners treat it as plant-only-with-extras. Contract Lifting Services hires under the dedicated CPA conditions are unambiguously a supply of construction services (the supplier provides the crane, the operator, the appointed person and the lift plan), so DRC applies in the contractor-supply chain. There is no plant-only argument available here.

Sub-hire and pass-through plant on a subcontractor invoice

Plant-hire AP gets more interesting once a chain forms. A subcontractor takes a telehandler on hire from Sunbelt or GAP under CPA Plant Only conditions, uses it on the main contractor's site for three weeks, and re-invoices the main contractor for the cost — sometimes at cost, sometimes at cost plus an agreed margin, often embedded inside the subcontractor's monthly application for payment rather than as a standalone VAT invoice. The JCT and NEC application for payment versus the VAT invoice distinction matters here because the main contractor is assessing an application, not paying an invoice, and the response mechanics differ.

The main contractor's AP team has to verify the pass-through line, and that means working back to the underlying CPA invoice that produced it. The verification job runs on three things. First, the underlying CPA invoice from the original owner has to support the pass-through cost — for cost matching, for confirmation that the on-hire and off-hire dates align with the dates the kit was actually on the main contractor's site (not on the subbie's yard or another site between hires), and for the VAT treatment per leg. Second, where the subcontractor charges cost-plus, the subcontract between main contractor and subcontractor governs whether the margin is allowed and at what rate; AP verifies the margin against the subcontract terms, not against the CPA invoice itself. Third, the dates on the CPA invoice and the dates the pass-through line covers have to match — a subcontractor charging the main contractor for plant time the subbie was using on a different job is a recoverable error.

DRC works leg by leg. Each invoice in the chain is treated separately, on its own facts:

• Owner to subcontractor. DRC applies if the plant is supplied with operator and the subcontractor is a VAT-registered, non-end-user customer in construction (the typical case). Plant-only hire to the subcontractor is goods, standard-rated.
• Subcontractor to main contractor. DRC applies if the subcontractor's onward supply is construction services and the main contractor is a non-end-user VAT-registered customer. A plant-only sub-hire pass-through that is just a recharge of goods is goods on the downstream leg too; a plant-with-operator pass-through (the subbie's operator using sub-hired plant, charged on as a labour-and-plant package) is construction services on the downstream leg, regardless of how the upstream leg was treated.

The failure modes the main contractor's AP catches: the underlying CPA invoice not supplied — the subbie cannot evidence the cost; on-hire and off-hire dates on the CPA invoice that don't match the dates the plant was on the main contractor's site; VAT treatment that flips inconsistently between the legs (DRC upstream, standard rate downstream with no end-user notification to explain it, and no plant-only-versus-plant-with-operator reason to justify it); margin charged that the subcontract does not allow, or charged at a higher rate than the subcontract permits.

The plant pass-through is one line in a wider review. The full assessment of the subcontractor's application — including pay-less-notice mechanics and statutory time limits — runs through the assess a subcontractor application for payment and issue a Pay Less Notice workflow. The plant lines fit inside that wider assessment; AP's job on the plant pass-through is to produce the verified figure that goes into the certified amount, not to run the certification process itself.

Recurring weekly invoices, the supplier master, and the AP review pack

The article so far has walked the line-by-line checks. The control that holds them together is the AP-master-data design — the supplier master, the purchase order, and the review pack that turns the unstructured supplier PDF into something the rest of the controls can actually run against. Without that design, the controls fire only on the invoices a vigilant AP clerk happens to spot.

Plant hire issues weekly invoices for the duration of the hire, and the recurring failure mode is straightforward. A hire ran for three months. The plant manager off-hired the kit on a Friday in July. A weekly invoice arrived in August charging through to mid-July, posted clean against the open PO, and went to payment because nothing flagged it. The meter ran past off-hire because nobody held the post-off-hire invoice for review.

The supplier-master pattern that prevents this is not exotic. Open a per-hire purchase order rather than a blanket-PO arrangement; set the expected weekly cadence at one invoice per week per PO; set the expected end date to the projected off-hire date plus a small buffer of one or two weeks for billing lag; and configure an exception flag in the AP system that holds any invoice arriving past the expected end date for plant-manager review before it posts. The design point is that the exception fires automatically. The AP clerk does not have to remember which hires off-hired last month; the system holds the late invoice and asks the question.

The AP review pack itself is the row-per-line structure that sits between the supplier's PDF (or portal export) and the AP processor's checks. One row per invoice line. Columns for the on-hire date, the off-hire date, the hire rate, the idle days and idle rate, the breakdown days, the dilapidation amount, the plant description, the project and cost code, and the DRC flag. With that table in front of the AP processor, every check from the earlier sections has a column to land in: the on-hire and off-hire dates compare against the plant manager's records, the idle rate compares against the working rate, the DRC flag is set per line rather than per invoice.

Pulling the supplier PDF or portal export into that structure is the prerequisite for running the rest of the controls at any kind of scale, and an AI tool that can extract weekly plant-hire invoice line items into a structured spreadsheet — turning the unstructured invoice into the row-per-line table the AP team works against — is the concrete way to produce it. A natural-language prompt describes the columns and the row granularity (one row per line item, repeating the invoice number on each row); the AI extracts to Excel, CSV, or JSON; and every output row carries a reference back to the source file and page number, so AP can cross-check against the original invoice without leaving the spreadsheet. The same prompt works whether AP is processing one weekly invoice or a month's worth across the hire ledger.

Three further pieces fit around the review pack. Where one weekly invoice covers plant moved across multiple sites in the week, the apportionment job has its own workflow — split a weekly hire invoice across multiple construction sites covers the mechanics, and the trigger here is simply that more than one project or cost code applies to a single invoice. Once the review is complete and the lines are verified, the plant-hire lines code construction supplier invoices to job, phase, and cost code the same way every other construction supplier invoice does — phase and cost code by project, with the DRC flag carried through to the VAT side of the posting. And plant hirers usually issue a monthly statement aggregating the weekly invoices, so the standard control to reconcile a UK supplier's monthly statement against the invoice ledger at month end applies to plant hire on the same principles as it does to builders' merchants.

Two pointers to keep this concrete. The major UK plant hirers an AP team typically processes are Sunbelt Rentals, Speedy, GAP Hire Solutions, Selwood, Brandon Hire Station, HSS Hire, and Nationwide Platforms (the latter for MEWPs). Each has an account portal where on-hire and off-hire confirmations, invoice history, and statement downloads live, and the portal is usually a more reliable evidence source than the emailed PDF. Construction-AP software where the per-hire PO, project-coded invoice posting, and DRC flagging features sit varies by platform: Eque2, RedSky, ConQuest, COINS, and Causeway are the construction-specific platforms; Sage 50, Xero UK, and QuickBooks UK serve the broader market with construction-AP add-ons or a chart-of-accounts setup that handles project coding and DRC flags. The features named are pointers, not a comparison.