Boiler service invoice template UK (2026): CP12, service plans and VAT

A boiler service invoice is a maintenance document, not an installation document, and that single distinction changes almost everything about how you bill it. A service visit is short, repeatable, often sold on a plan, frequently paid by somebody who was never in the property, and it usually sits alongside a safety record that has its own legal life. Get the invoice wrong and you are not just waiting for money — you are handing a letting agent a reason to park the payment until the next accounts run.

This page is about servicing and maintenance billing: annual services, service-and-safety-check combinations, landlord gas safety records, letting agent purchase orders, block invoicing across a portfolio, service plans and monthly payments, callouts and out-of-hours rates, abortive and no-access visits, and the awkward moment when a service turns into a repair or a replacement and the invoice has to change shape halfway through. If you want the general template for a gas engineering business — stage payments on a supply-and-fit, flue works, heat pumps, full copy-paste field lists — read the gas engineer invoice template instead. This page deliberately does not repeat it.

Three things drive the whole document. Who pays decides whether you are looking at a consumer invoice, an agent purchase order or a CIS subcontract. What you actually did decides the labour and parts lines and whether the visit stopped being a service. What the work is for VAT decides the rate, and a straightforward gas boiler service in someone's home is standard-rated — the reliefs people quote at you almost never apply to a service visit.

Every figure below is illustrative only. They are not market rates, not a price list and not a recommendation on what to charge. Rules were checked against GOV.UK, HMRC manuals, HSE guidance and legislation.gov.uk on 3 September 2026. This is general information for UK trades, not tax, legal or gas safety advice, and it is not a substitute for the current text of the Gas Safety (Installation and Use) Regulations 1998 or your registration body's own procedures.

Related reading: Gas Safe registration in the UK · allowable expenses for a gas engineer · recurring invoices for maintenance contracts · how to charge callouts and emergency work fairly · how to invoice a client as a UK tradesperson.

In short

Service billing is not installation billing

Installation invoicing is about stages, deposits, materials on order and variations. Servicing invoicing is about volume, repeatability and evidence. You will send far more service invoices than installation invoices, each for a smaller amount, often to a payer who needs to reconcile dozens of them at once.

Because the money is small and the volume is high, a small failure rate hurts more than it does on installation work. Two hundred service invoices a quarter with five unmatched means five phone calls, five re-issues and five aged debtor lines you will still be looking at in six weeks.

What must appear on a boiler service invoice

Start with the legal floor. GOV.UK's invoices — what they must include sets out the minimum for any UK business invoice, plus extra requirements depending on how you trade.

If you are VAT-registered and your customer is VAT-registered, you must issue a VAT invoice, which carries more detail. HMRC lists the required particulars in VAT Notice 700, section 16.3.

Threshold check while we are here: you must register for VAT if taxable turnover for the last 12 months goes over £90,000, or you expect to go over £90,000 in the next 30 days (GOV.UK). A service round with a few hundred plan customers gets there faster than people expect.

The paperwork your service invoice sits next to

The invoice is a commercial document. It is not the safety record, and it never satisfies a gas safety duty. Under regulation 3 of the Gas Safety (Installation and Use) Regulations 1998, nobody may carry out work on a gas fitting unless they are competent, and an employer or self-employed person must be a member of a class of persons approved by the HSE for that purpose — in practice, Gas Safe Register.

Regulation 26(9) also requires that immediately after working on a gas appliance you examine the effectiveness of any flue, the supply of combustion air, its operating pressure or heat input (or combustion performance where examining pressure or heat input is not reasonably practicable), and its operation for safe functioning — then take all reasonably practicable steps to notify any defect to the responsible person and, where different, the owner. That is the shape of a service, and it is why "we serviced it" is a weak invoice line while "annual service, combustion analysis and flue check carried out, results recorded on service record ref …" is a strong one.

For a rented property, regulation 36(3)(c) sets out exactly what the landlord's safety-check record must contain. The industry calls the form a CP12; the Regulations simply call it a record. Your invoice should reference it, not duplicate it.

Retention and issue are legal duties on the landlord, not on you, but knowing them keeps you useful: the record must be retained until there have been two further checks of that appliance or flue (or, where the appliance is removed, for two years from the last check); a copy must be given to each existing tenant within 28 days of the check; and a copy of the last record must be given to any new tenant before they occupy. Regulation 36A allows the annual check to be carried out up to two months before the deadline date while keeping the original deadline — useful when an agent wants a whole block done in one week. HSE's landlord gas safety FAQs confirm the same duties can sit with the agent where the management contract says so.

If you find something dangerous, that is a safety process with its own paperwork — a warning or advice notice under the unsafe situations procedure your registration body issues, with the appliance classification recorded on it. Separately, under regulation 11(2) of RIDDOR 2013, an approved person who has enough information to decide that the design, construction, installation, modification or servicing of a gas fitting is or could have been likely to cause death, loss of consciousness or hospitalisation because of gas leakage, incomplete combustion or inadequate removal of products of combustion must report it to HSE within 14 days. Put the notice reference on the invoice; never put the safety outcome in the payment terms.

Worked example A — annual boiler service for a homeowner (illustrative)

A VAT-registered sole trader services a combination boiler in a lived-in house. No fault found, one consumable replaced. Figures are illustrative only.

Notes that belong on the face of this invoice: the appliance make, model and GC number; the service date as the supply date; the service record reference; and the payment terms. If nothing was found, say so — "no defects identified at the time of the visit" costs one line and prevents an argument next winter.

Why 20%? Because a boiler service in residential accommodation is a standard-rated supply of services. The reliefs in VAT Notice 708/6 are about installing qualifying energy-saving materials, or about grant-funded heating work for a qualifying person. Neither describes an ordinary annual service someone books over the phone.

Billing landlords, letting agents and portfolios

The person in the property is almost never the person paying. Decide the payer at booking, because the invoice header cannot be fixed later without re-issuing.

Purchase orders are the whole game with agents. An agent's accounts system matches on the PO and the property. If either is missing, your invoice sits in a suspense pile until somebody has time to investigate, which on a £90 service is nobody.

For a portfolio, you have two workable patterns. Per-property invoices are cleaner for recharging to individual landlords and easier to dispute in isolation. Schedule invoices — one invoice with a line per property — are faster to raise and reconcile if the agent's system accepts them. Ask before you choose; the agent's ledger structure decides, not your preference.

Worked example B — landlord gas safety check plus service, billed to an agent (illustrative)

Note how the safety check and the service are separate lines even though they were one visit. Agents recharge the safety check to the landlord as a compliance cost and often treat the service differently. One merged line invites a query.

Service plans and recurring invoicing

A service plan is a different commercial animal from a visit. The customer is buying cover over a period: a scheduled annual service, sometimes breakdown attendance, sometimes parts. Your billing has to reflect that or your arrears reporting becomes meaningless.

Practical rules that keep plans clean:

• Invoice the plan, then invoice the extras separately. A plan invoice says "Boiler care plan — monthly instalment, September 2026". A chargeable repair during the plan gets its own invoice with its own number.

• Show what the plan covers on the invoice or on a linked terms page. When somebody disputes a parts charge nine months in, you want the exclusion in writing on the document they paid.

• Say what happens if the plan is cancelled before the annual service. If you have already carried out the service in month two and the customer cancels in month three, your terms decide whether you can invoice the balance. Set that out before the first collection, not after.

• Keep the plan reference on every related invoice. "Plan PL-1044" on the plan instalment, the repair invoice and the parts invoice makes the customer's history readable in one search.

VAT on a plan versus a visit. If you are VAT-registered, a service plan is still a taxable supply of services, and the ordinary tax point rules apply — a payment received or a VAT invoice issued can create the tax point ahead of the visit. That is genuinely different from a one-off service where the visit and the invoice sit on the same day. If your plan spans a rate change, a period end, or a customer who leaves mid-term, the tax point matters. Check your position with whoever prepares your VAT return rather than assuming the visit date governs. The mechanics of recurring billing are covered in recurring invoices for maintenance contracts.

Insurance-style plans are a separate question. If a plan is structured so that you are effectively providing insurance rather than maintenance, the tax and regulatory treatment is not the same as a straightforward maintenance contract. That is a question for your accountant and, potentially, for regulated-activity advice — this guide will not guess at it.

Callouts, out-of-hours and part-hour billing

Servicing rounds generate callouts, and callouts generate arguments if the rate structure is invented at the door. Publish the structure, quote it at booking, and repeat it on the invoice.

Illustrative structure only — these are not recommended prices:

Two rules make part-hour billing defensible. First, state the increment: "first hour included in the callout, then charged in 15-minute increments" is checkable; "plus time" is not. Second, show the arithmetic on the invoice: callout £X, then 0.75 hr at £Y, rather than a single number the customer has to trust.

For a landlord or agent, add one more: who authorised the out-of-hours attendance. An emergency callout to a tenant that the agent never sanctioned is the most commonly refused line on any maintenance ledger. There is more on structuring this in how to charge callouts and emergency work fairly.

No access, gaining access and abortive visits

HSE's guidance to landlords on access is worth knowing because it shapes what the agent expects from you: a landlord has to show they took all reasonable steps to comply, and HSE recommends leaving a notice recording the attempted check and writing to the tenant. Your no-access documentation is part of that evidence chain, which is exactly why a well-documented abortive-visit charge gets paid and a bare one does not.

When a service turns into a repair

A service becomes a repair the moment you fit something that was not planned or spend time diagnosing rather than checking. The invoice has to make the boundary visible.

Three habits do most of the work:

1. Get authorisation before you fit. A text message with the part, the price and the words "OK to proceed" is enough for a homeowner. For an agent, get a variation PO or an emailed approval — the original PO limit will not stretch.

2. Split labour and parts. Not because tax requires it on a domestic job, but because it makes the invoice readable and it is the split you will need if the same work is ever billed to a contractor under CIS.

3. Say who approved it and when. One line: "Repair authorised by J. Ellis (Northgate Lettings) by email, 14 September 2026."

Worked example C — service that became a repair (illustrative)

Warranty and manufacturer-warranty work. If the appliance is inside a manufacturer's warranty and the manufacturer or their agent is paying, you are billing a business, not a householder — different payer, different terms, usually a claim reference and often a fixed schedule rate. Do not send the householder an invoice for work the manufacturer is covering, and do not put warranty work and chargeable work on the same invoice line. If part of the visit is covered and part is not, two invoices to two payers is cleaner than one invoice with a confusing credit on it.

If you fitted a part under your own workmanship guarantee, invoice it at nil with the reason stated ("re-attend under 12-month workmanship guarantee — no charge") rather than leaving the visit off the ledger entirely. You want the job history, and so does the customer.

When a service turns into a replacement — and which VAT rate applies

This is where people get the VAT wrong, usually because somebody half-remembers a rate from a heat pump job.

Read that table twice before you put 5% on a boiler repair. The reduced rate for repair and maintenance of a central heating system in Notice 708/6 section 3.3 is inside the grant-funded part of the notice, and it depends on a qualifying person and a qualifying grant scheme. A private customer ringing up for a service does not become a qualifying person because the boiler is old.

Also: the replacement conversation is a new job. New survey, new quote, new invoice, possibly stage payments and a deposit, plus Building Regulations obligations that a service never triggers. Installing a heat-producing gas appliance, and installing a heating or hot water system or its associated controls, are both in Schedule 3 to the Building Regulations 2010 as work that can be self-certified by a person approved under regulation 3 of the Gas Safety (Installation and Use) Regulations 1998. GOV.UK's competent person scheme page explains that a registered installer can self-certify and will give the customer a certificate within 8 weeks of completion. The technical requirements sit in Approved Document J (combustion appliances and fuel storage systems) and Approved Document L (conservation of fuel and power). Reference the commissioning checklist and the notification on the installation invoice — the service invoice never carries them.

CIS: which side of the line a boiler service sits on

The public GOV.UK summary of what CIS covers lists "installing systems for heating, lighting, power, water and ventilation" as construction work, which is where the confusion starts. HMRC's manual is more precise.

CISR14090 explains that the building-service-systems provision (FA04/S74(2)(c)) covers installation only — "it only applies to installation of these systems, not their repair or maintenance. Neither does it apply to their alteration or extension." The same page goes further and says that even where the replaced item is a significant component such as a central heating boiler, its replacement "does not constitute 'the installation of a system of heating' and therefore will not fall within CIS."

So: a domestic boiler service is normally not a construction-operation subcontract. What changes when you start working for a housing association or a main contractor is not the service itself but the surrounding contract. If your contract with them is a planned-maintenance servicing contract and nothing else, the servicing element is not a construction operation. If the same contract also covers system installations, renewals with building works, or making good, you are into mixed-contract territory and CIS can apply to payments under that contract.

Where CIS does apply to you as a subcontractor, the deduction is 20% if you are registered, 30% if you are not, and 0% with gross payment status. It comes off the labour element only — never off VAT, and never off the direct cost of materials you paid for on that contract (CISR15060). That is precisely why the labour/parts split you already do on repair invoices is worth keeping as a habit: the day a contractor puts you on a renewals package, your invoice is already in the right shape.

Domestic reverse charge on subcontracted heating work

The VAT domestic reverse charge follows CIS reporting. HMRC's supplier guidance says you must use the reverse charge if you are VAT-registered in the UK, you supply building and construction services, and all of the following are true.

Two consequences for a servicing business. First, a private householder is never in scope — there is no CIS reporting and no VAT-registered customer, so a domestic boiler service is a normal VAT invoice with VAT charged in the usual way. Second, because a service visit is normally not reported under CIS at all, the reverse charge usually does not bite on servicing even when the customer is a VAT-registered contractor. It becomes relevant when you take on installation work for that contractor. Full detail: domestic reverse charge VAT for construction.

Worked example D — heating installation subcontract with CIS and reverse charge (illustrative)

A VAT-registered limited company installs a complete new central heating system as a subcontractor to a VAT-registered main contractor doing a refurbishment. The contractor reports the payment under CIS and has not given an end-user statement. The subcontractor is CIS-registered for net payment.

Wording that must appear: a reverse-charge statement telling the customer they are required to account for the VAT, and the amount of VAT due (or the rate) shown for information — HMRC's guidance sets out what your invoices and other documents need to say. Note that the same engineer, on the same estate, servicing those boilers a year later under a maintenance contract would very likely be invoicing normally with VAT charged and no CIS deduction. Same customer, different work, different invoice.

Getting paid: terms, statutory interest and plan arrears

Service work lives or dies on collection speed because the individual amounts are too small to chase properly. Set terms that fit each payer type instead of using one default.

For business-to-business debts, the Late Payment of Commercial Debts framework gives you statutory interest at the Bank of England base rate plus 8% where no different contractual rate applies, plus a fixed sum for each debt (GOV.UK).

Those amounts are set by the legislation, and you can also claim reasonable debt-recovery costs on top. Two cautions. This is a B2B regime — a homeowner is a consumer and this does not apply to them. And if you decide to add interest to a debt, GOV.UK's own guidance is to send a new invoice for it rather than editing the original.

On a service round, the fixed sum is often larger than the debt. A £95 unpaid service invoice to a limited company landlord attracts a £40 fixed sum plus interest — which is precisely why a polite, early, well-referenced reminder beats a legal threat you will never follow through.

Record keeping: invoices, gas records and MTD

Three different clocks run at once, and people routinely quote the wrong one.

Your own service records are separate again, and worth keeping longer than the minimum: on a plan customer you want the full appliance history in one place, because that history is what justifies a repair recommendation three years later. There is more on the invoice side in how long to keep invoices for HMRC.

Making Tax Digital for Income Tax is about digital records and quarterly updates — it is not a replacement for the tax return. HMRC's eligibility guidance sets the phasing by qualifying income: over £50,000 for 2024 to 2025 meant starting from 6 April 2026; over £30,000 for 2025 to 2026 means from 6 April 2027; over £20,000 for 2026 to 2027 means from 6 April 2028. You still need to submit a Self Assessment return for the tax year before you start. A high-volume service round with hundreds of small invoices is exactly the kind of business where keeping records digitally as you go beats a shoebox in March.

How InvoiceAdept fits a service and maintenance round

InvoiceAdept is invoicing software for UK trades. On a servicing business it is useful for the boring, repeated part: raising the same invoice shape hundreds of times with the right references on it, keeping the property address and PO where an agent's accounts team will actually see them, and being able to search a property's invoice history when somebody queries a charge from eighteen months ago.

• Free: five invoices a month.

• Pro £7.99/month: higher limits and WhatsApp send.

• Pro+ £12.99/month: CIS-focused features for subcontractor billing.

What it does not do, and will not pretend to do: it does not issue landlord gas safety records, warning notices, Building Regulations certificates or commissioning checklists; it does not decide your VAT rate or your CIS status; and it does not file VAT returns, CIS300 returns, MTD quarterly updates or Self Assessment. Those stay with your registration body, your accountant and HMRC-compatible software.

Mistakes that stall a boiler service invoice

FAQ

Is a boiler service standard-rated for VAT?

For a VAT-registered engineer, an ordinary boiler service in a home is standard-rated. The zero rate in VAT Notice 708/6 applies to installing specified energy-saving materials in residential accommodation between 1 May 2023 and 31 March 2027 (reverting to 5% from 1 April 2027), and a conventional gas boiler is not on that list. The 5% rate for repair and maintenance of a central heating system sits in the notice's grant-funded section and depends on a qualifying person and a qualifying grant scheme.

Do I have to put my Gas Safe registration number on the invoice?

It is not one of the invoice fields GOV.UK requires, so legally the invoice does not need it. The landlord gas safety record is different: regulation 36(3)(c) requires the name and signature of the individual carrying out the check and the registration number of that individual or their employer. Most engineers put the number on the invoice anyway, because customers look for it.

Should the annual service and the landlord gas safety check be separate lines?

Yes, even when they are one visit. Agents and landlords account for the compliance check differently from the maintenance, and separating them removes the most common query. It also makes it obvious what was and was not done if the property changes agent.

Who do I invoice — the landlord, the agent or the tenant?

Whoever you contracted with. If a managing agent instructed you as principal, invoice the agent against their purchase order. If the agent instructed you on the landlord's behalf and said so, invoice the landlord and send it to the agent. HSE's landlord FAQs confirm that where the management contract puts the gas safety duties on the agent, the same duties apply to the agent — so agents usually want the invoice and the record.

Can I charge for a visit where nobody was home?

That is a commercial matter between you and the payer, and it depends on your terms. Publish an attendance or abortive-visit charge, agree it at booking, and document the visit — arrival and departure times, the card you left, and any call attempts. Landlords and agents are generally receptive because HSE expects them to show they took all reasonable steps to get the check done, and your record is part of that evidence.

Does a domestic boiler service come under CIS?

Normally no. CISR14090 says the building-service-systems rule covers installation only, not repair or maintenance, and that even replacing a central heating boiler is not "installation of a system of heating". There is also no contractor in an ordinary householder job. Installing a complete new central heating system for a contractor is a different answer — that is within CIS.

What changes if I subcontract to a housing association or main contractor?

Check three things before you invoice: whether the payment is being reported under CIS; if so, your CIS registration status, because the deduction is 20% registered, 30% unregistered or 0% with gross payment status, and it comes off labour only, never off VAT or the direct cost of materials; and whether the domestic reverse charge applies, which it can only do where the payment is reported under CIS and the customer is VAT-registered and has not given an end-user statement.

How should I invoice a monthly service plan?

Invoice the plan period as its own recurring invoice with a plan reference, and invoice chargeable extras separately with the same reference. Keep the covered/excluded list somewhere the customer has agreed to. If you are VAT-registered, remember that a payment or an invoice can create the tax point before the visit happens — check the treatment with whoever prepares your VAT return.

How long do I have to keep service invoices and gas records?

Different clocks. Sole traders keep business records at least 5 years after the 31 January submission deadline for the relevant tax year; limited companies keep records 6 years from the end of the last company financial year; VAT records are generally kept at least 6 years. The landlord's safety-check record must be retained until there have been two further checks of that appliance or flue (or two years from the last check where the appliance is removed), with a copy to each existing tenant within 28 days and to any new tenant before they move in.

Does InvoiceAdept issue the CP12 or file my returns?

No. It creates, sends and stores invoices. Landlord gas safety records, warning notices, Building Regulations notifications and commissioning checklists all come from you and your registration body. VAT returns, CIS300 returns, MTD updates and Self Assessment go through HMRC-compatible software or your accountant.

About this guide

This guide is for UK gas and heating engineers who service and maintain boilers, and for the landlords and letting agents who pay them. Last reviewed 3 September 2026.

Sources checked for this version: GOV.UK — invoices, what they must include; VAT Notice 700, section 16.3; GOV.UK — when to register for VAT; VAT Notice 708/6 — energy-saving materials and heating equipment; HMRC CISR14090, CISR14020, CISR14120, CISR14220 and CISR15060; GOV.UK — what is the Construction Industry Scheme and CIS subcontractor payments; HMRC — VAT domestic reverse charge for building and construction; Gas Safety (Installation and Use) Regulations 1998 regulation 3, regulation 26, regulation 36 and regulation 36A; HSE landlord gas safety FAQs; RIDDOR 2013 regulation 11; Building Regulations 2010 Schedule 3 and GOV.UK competent person schemes; Approved Document J and Approved Document L; GOV.UK — late commercial payments and debt recovery costs; GOV.UK — self-employed records, company and accounting records and VAT Notice 700/21; GOV.UK — check if you are eligible for Making Tax Digital for Income Tax.

All monetary examples are illustrative and are not market prices, recommended rates or a price list. VAT, CIS and gas safety outcomes turn on the specific contract, customer, property and evidence — check the current GOV.UK, HSE and legislation text and take professional advice on anything uncertain. Nothing here is tax, legal or gas safety advice, and nothing here replaces your registration body's procedures.

InvoiceAdept is invoicing software from Tech Me Today Ltd, Companies House 15917255, ICO registration ZB944663. Free: five invoices a month. Pro: £7.99/month. Pro+: £12.99/month with CIS features. It does not issue gas safety documentation and does not file returns to HMRC.