Plant Hire Billing: 5-Day and 3-Day Weeks

Ten days on hire. A £150-a-week item. Depending on the charging method in your terms, the bill is £214.29, £240 or £300.

The difference is how a part week is charged. This guide sets out where hire billing rules come from, four ways to charge a part week with worked figures, how to bill a long hire as it runs, and how loss, damage waivers, VAT and CIS work on hire.

It is written for UK firms that hire kit out. It is not legal or tax advice, and your own terms decide what you can charge.

Where the rules come from

Most of what decides a hire bill is in your own terms and rate card, not in law.

Many UK firms hire on the Construction Plant-hire Association (CPA) Model Conditions for the Hiring of Plant. The current edition, as far as we could find in October 2026, dates from 2021; copies are headed October 2021. CPA says it made no fundamental changes to the principal effects of the 2011 conditions, which stay valid for hires already running under them. The Model Conditions are for business-to-business hire only: CPA publishes separate conditions for consumers.

The conditions are CPA copyright and a members' resource. Hire firms reproduce them on their own sites, sometimes with their own edits, so treat any copy you find online as that firm's version and check the copy your contract actually incorporates. Copies differ in wording, and even in the hours of the working day.

When the hire clock runs

Under the CPA conditions the hire period starts when the plant leaves the owner's depot, or the place it was last working, and runs until it is back at the owner's depot or another agreed place. It includes time in transit and time left on site over evenings, nights, weekends and holidays.

Four other points in the CPA conditions affect the bill:

The owner confirms the off-hire. Under the 2021 text a hirer can off-hire in writing, including by app, but the off-hire is accepted only once the owner issues an off-hire confirmation. Issue one for every off-hire and keep a copy.
Kit not ready for collection goes back on hire. If plant is not made available for collection as agreed, it is treated as back on hire straight away, and the hirer stays responsible for it.
Daily hire and weekends. On a daily rate that is not tied to a minimum number of hours, a Saturday or Sunday is not charged unless the plant is worked that day. Copies of the 2021 text also charge for weekends when the hirer asked for delivery to site or for the plant to be on standby. On weekly or monthly hire, the weekly or monthly rate applies whatever the hours.
Idle time. If plant is prevented from working for a complete working week, for a reason the idle-time clause in your copy covers, the charge is two thirds of the hire rate, unless the owner agrees another rate in writing.

Four ways to charge a part week

The CPA conditions charge odd days at the start and end of a hire pro rata, rather than rounding a part week up to a full week, and their working week runs Monday to Friday unless the contract says otherwise. The four methods below are pricing conventions a firm sets in its own rate card and terms, not CPA rules. Whole weeks only always charges a part week as a full week, and a 3-day week does once the part week reaches three days (in the figures below, 4 days cost £150). Both depart from that CPA clause, so if you use one on CPA terms it has to be in the terms the hire is actually on.

Here are four ways to do it:

Weekly, extra days pro rata. Each whole week costs the week rate, and each extra day costs a seventh of it.
5-day week. Each whole 7-day week costs the week rate, and each day past it costs a fifth of the week rate, so five or more extra days cost a week.
3-day week. Each whole 7-day week costs the week rate, and each day past it costs a third of the week rate, so three or more extra days cost a week.
Whole weeks only. Any part of a week costs a full week.

As defined here, a part week never costs more than a full week. A firm can also set its own day rate for an item instead of dividing the week rate, which changes the pro rata, 5-day and 3-day figures but not whole weeks.

Here is what a £150-a-week item costs under each method, counting every calendar day it is on hire:

4 days: £85.71 pro rata, £120.00 on a 5-day week, £150.00 on a 3-day week, £150.00 in whole weeks.
10 days: £214.29 pro rata, £240.00 on a 5-day week, £300.00 on a 3-day week, £300.00 in whole weeks.
17 days: £364.29 pro rata, £390.00 on a 5-day week, £450.00 on a 3-day week, £450.00 in whole weeks.

Two more choices change these figures, so put them in your terms in writing: whether the off-hire day itself is charged, and whether you count calendar days or working days only. Minimum hire periods are set by each firm's own terms too, so state yours.

Long hires: bill as you go

For VAT, hiring equipment is a continuous supply of services. There is no single tax point at the end of the hire: each VAT invoice you issue, or payment you receive, whichever comes first, creates a tax point for that amount. So if you invoice a long hire every few weeks or monthly, rather than waiting until the kit comes back, the VAT is accounted for invoice by invoice.

The safe way to bill part way through is for each invoice to charge the hire to date less what earlier invoices on the same hire already billed. If each invoice instead prices its own stretch as if it were a new hire, every stretch can carry its own part week: on a 3-day week at £150, eight days billed once cost £200, but billed as two 4-day invoices they cost £300. Put the customer's purchase order number on every invoice, so their accounts team can match each one to it.

Any long-hire discount is a commercial term: you set it in your rate card or agree it with the customer.

Loss, damage and damage waivers

Under the CPA conditions the hirer must make good to the owner all loss of or damage to the plant during the hire, from whatever cause, except fair wear and tear. When plant is lost or damaged, hire charges continue at idle-time rates until a settlement is agreed, and copies of the 2021 text also say the settlement must be paid within 21 calendar days of the agreement, or idle-time charges can be reinstated from the date of the agreement.

A damage waiver is a contract term, not an insurance policy. The hirer pays a fee, usually a percentage of the hire charge, and is relieved of some or all of that liability; the fee, excess and theft terms vary by firm. CPA also devised its own version, separate from the Model Conditions: the subrogation waiver, which an owner can offer only with its insurer's prior agreement. The hirer gets an interest in the owner's insurance, so the owner's insurer settles the owner's claim and does not pursue the hirer. CPA says the fee is usually 15 to 20% of the hire rate, and the hirer may still pay an excess. If a hirer declines a waiver, CPA's guidance is that they should arrange their own hired-in plant insurance, so ask for evidence of it before the kit goes out.

Keep loss and damage charges apart from hire charges on your invoices, because the VAT can differ.

VAT and CIS on hire

Hiring out plant or tools is a supply of services for VAT, not of goods, because only possession passes.
Plant and tools hired without an operator are standard-rated at 20%, even when they are used on a zero-rated new-build job. Plant hired with an operator takes the VAT liability of the work it is used for.
Plant hired without an operator is outside the Construction Industry Scheme, so the domestic reverse charge does not apply to the hire charge. Plant hired with an operator is within CIS, and the reverse charge can apply.
Compensation for hired goods lost or destroyed while out of the owner's control is outside the scope of VAT. A charge for keeping kit past the agreed term is extra hire and carries VAT, and since 1 April 2022 HMRC treats early termination fees as further payment for the supply, so they carry VAT too. Charges for damage, as opposed to loss, need checking on their own facts.

Hiring to sole traders and small partnerships

Some hire terms cap hires to sole traders, partnerships and other unincorporated hirers at three consecutive months. The reason is the Consumer Credit Act 1974: a hire of goods to an "individual" that can last more than three months is a consumer hire agreement, regulated unless exempt, and an "individual" includes a sole trader and a partnership of two or three partners. If your terms let a hire to a sole trader or small partnership run past three months, take advice on whether it is regulated.

A private customer is an "individual" too, so the same three-month point applies to them. The CPA Model Conditions are not for consumer contracts: under the Consumer Rights Act 2015 a consumer is an individual acting wholly or mainly outside their trade, business, craft or profession.

Running it in Field Forge

Field Forge's Equipment Hire works the bill out once you have chosen how you charge. It is available the moment an admin or owner switches it on in Settings. It counts calendar days, and does not charge the off-hire date itself unless Field Forge sets your company up to charge it.

You choose one charging method for the company: weekly with extra days pro rata, a 3-day week, a 5-day week or whole weeks only. Each hire product has a week rate and an optional day rate, and a part week never costs more than a week.
A hire keeps the charging rules and rates it was confirmed with, so a later change to your rates does not reprice a running hire.
Bill to date raises one invoice for what the hire has earned so far, less what earlier invoices on the same hire billed, with the customer's PO on it. Nothing is billed automatically.
If you offer a long-hire discount or a damage waiver, it is applied at the percentage you set. Loss and damage always go on their own invoice.

Sources

CPA hire conditions, Construction Plant-hire Association. The clause detail above comes from hire firms' published copies of the Model Conditions, mostly of the 2021 text, not from CPA's own text, which is for members. Check the copy your contract incorporates.
Subrogation (damage) waiver, Construction Plant-hire Association
Value Added Tax Act 1994, Schedule 4, legislation.gov.uk
VAT Construction manual, VCONST02740: plant hire, HMRC
VAT Time of Supply manual, VATTOS9160: continuous supplies, HMRC
Construction Industry Scheme Reform manual, CISR14260: plant hire, HMRC
VAT domestic reverse charge for building and construction services, HMRC
Revenue and Customs Brief 2 (2022): VAT on early termination fees and compensation payments, HMRC
Consumer Credit Act 1974, section 15 and section 189, legislation.gov.uk
Consumer Rights Act 2015, section 2, legislation.gov.uk

Plant Hire Billing Explained: Pro Rata, 5-Day and 3-Day Weeks