Air conditioning invoice template UK (2026): split systems, CIS and VAT

An air conditioning invoice has to show what was surveyed, pipe-run, hung, charged, commissioned and handed over - not a vague "AC as agreed" or "air con works" line. "Supply and install air conditioning" does not tell a householder whether they received a single wall-mounted split, a multi-split with three indoor heads, a ducted system, a cassette in a commercial ceiling, a VRF/VRV package, or a portable unit that was only delivered with no install. It does not tell a main contractor's QS which plot, purchase order or M&E package to release. It does not tell a CIS contractor how much is labour and how much is the direct cost of the outdoor unit, indoor heads, copper pipe, condensate pump, brackets, electrics and refrigerant charge you paid for.

This page is the air conditioning / split system / multi-split / VRF money page for UK refrigeration and air-conditioning installers, F-Gas registered engineers and M&E subcontractors. It deliberately differs from sister guides you should open when the defined product is different:

• Heat pump invoice template UK - ASHP/GSHP/WSHP heating packages; Notice 708/6 ESM treatment can apply to qualifying heat pumps - ordinary comfort cooling / air conditioning generally does not

• EV charger invoice template UK - wallboxes and workplace charging, not AC plant

• Gas engineer invoice template UK - gas appliances and heating service lines

• Electrician invoice template UK - dedicated circuits and consumer-unit work that may sit beside an AC install

• Solar panel invoice template UK - PV arrays, not cooling

• Insulation invoice template UK - fabric insulation products

• Builder invoice template UK - whole-build packages that may include AC as a line, not a substitute for this guide

Who pays matters. Billing a private householder for air conditioning on their own home: normal invoice, no CIS. Billing a main contractor, developer, fit-out principal or housing contractor for installation of systems of air-conditioning: typically within CIS under HMRC's CISR14090 (building service systems - installation of systems of air-conditioning). Soften absolute claims: the facts of the contract matter. Under that manual framing, installation of an air-conditioning system is typically within scope when a contractor pays you; repair, maintenance and replacement of parts are generally outside; alteration or extension of an existing system is generally outside unless mixed with other construction operations that pull the contract in (CISR14020 / CISR14030). Soften if you only supply units with no install - CISR14220 keeps manufacture/delivery of building components alone outside CIS. Private householders are not CIS contractors - see CISR12030 and the public CIS overview.

VAT needs careful wording and a clear contrast with the heat pump sister page. Ordinary comfort cooling / air conditioning installs are usually standard-rated at 20% if you are VAT-registered. Do not claim Notice 708/6 zero-rate for ordinary air conditioning or comfort cooling. Heat pumps can sit under Notice 708/6 as energy-saving materials / heating equipment when residential (or relevant charitable) conditions are met - that is a heat pump analysis on the heat pump invoice template, not a free pass for cooling plant. Soften: check the live notice; InvoiceAdept does not decide VAT rates. Supply without install is usually standard-rated. Never reverse-charge a householder. Domestic reverse charge, when it applies, is a contractor-to-contractor VAT-registered construction supply-chain issue - not a domestic householder issue. See also VAT Notice 708 for buildings and construction context, and our domestic reverse charge invoice guide when the customer is a VAT-registered contractor and the supply is eligible.

This guide gives copy-paste fields, labour/materials splits for split, multi-split and VRF packages, deposits and stage payments, CIS and VAT scenarios, F-Gas / REFCOM / Building Control / electrical certificate contrasts, late-payment pointers (Bank Rate + 8% where statutory interest applies between businesses), and a long FAQ. Figures are illustrative only, not UK market rates or a price list. InvoiceAdept does not decide CIS or VAT status and does not file CIS300, VAT returns, Making Tax Digital updates or Self Assessment to HMRC. It does not issue F-Gas certificates, REFCOM paperwork, Building Control certificates, electrical certificates or manufacturer warranties.

Related templates: heat pump, EV charger, gas engineer, electrician, solar panel, insulation, builder, how to invoice a client, deposit invoice, domestic reverse charge, late payment rights.

Rules and links were checked for this guide on 10 September 2026. General information only, not tax, legal, Building Regulations, F-Gas, electrical or install certification advice. InvoiceAdept is from Tech Me Today Ltd, Companies House 15917255, ICO ZB944663.

In short

Start by identifying who pays you, what system you are installing (wall split, multi-split, ducted, cassette, VRF/VRV), whether the job is a new system install or repair/maintenance on existing plant, whether equipment must be ordered before work starts, and whether the contract is supply-only or supply-and-install.

Private householder, own-home air conditioning: no CIS. The householder is not a CIS contractor (CISR12030 / public CIS guide). If VAT-registered, ordinary comfort cooling installs are usually 20% standard-rated. Do not invent Notice 708/6 zero-rate for ordinary AC. Show survey/design, pipe/electrics first fix, outdoor unit, indoor heads, refrigerant charge narrative, commission and snag. Never reverse-charge a householder.

Air conditioning package for a CIS contractor: typically within CIS when a contractor pays you for installation of systems of air-conditioning (CISR14090). Soften: repair/maintenance and replacement of parts are generally outside; alteration/extension of existing systems is generally outside unless mixed with other construction ops (CISR14020 / CISR14030). Split labour from materials at direct cost (CISR15060 / CISR15090). Free-issue outdoor unit from the main contractor is not your materials.

Manufacture and delivery of units only (no install): generally outside CIS (CISR14220). A mixed contract that supplies the unit and includes installation can pull the whole contract into CIS (CISR14020 / CISR14030). Portable supply-only with no install is usually a materials/sales invoice, not a CIS labour package.

VAT: ordinary comfort cooling / AC is usually standard-rated 20% if registered. Do not claim Notice 708/6 zero-rate for ordinary AC - contrast with qualifying heat pumps on the heat pump sister page. Supply-only is usually standard-rated. Never reverse-charge a householder. Domestic reverse charge only when eligible contractor-to-contractor rules apply on standard-rated construction supplies.

Take a deposit before ordering outdoor units and indoor heads if your terms require one. Stage survey/design, equipment order deposit, first fix pipe/electrics, second fix heads/commission, and snag. Keep variations separate. Use the invoice generator for a first invoice. InvoiceAdept Free is £0 for five invoices per month. Pro is £7.99 excl VAT and includes WhatsApp send. Pro+ is £12.99 excl VAT and includes CIS. Stripe's own fees apply (UK cards typically 1.5%+20p), but InvoiceAdept adds no platform fee.

Who this air conditioning invoice template is for

This template is for UK air-conditioning and refrigeration installers, F-Gas registered engineers, M&E subcontractors and builders who need readable invoice lines for split systems, multi-splits, ducted plant, cassettes and VRF/VRV packages. It covers the paperwork pattern, not a price list and not an F-Gas, REFCOM, Building Control or electrical certificate.

• Split-system installers (single outdoor + one indoor head)

• Multi-split crews (one outdoor + multiple indoor heads)

• Ducted / concealed indoor unit installers

• Cassette and commercial ceiling-grid installers

• VRF/VRV package installers on larger commercial or multi-zone domestic jobs

• Electricians billing dedicated circuits or isolators as part of an AC package (or separately)

• Builders who include air conditioning in residential or fit-out packages

• Subcontractors to main contractors on M&E / building services packages

• Sole traders and limited companies who need CIS and VAT lines that match the payer

• Firms doing repair and maintenance call-outs who still need clear invoices that do not pretend a service visit is a full system install for CIS purposes

If your day job is a qualifying residential heat pump package, use the heat pump guide (including Notice 708/6 notes). If the defined product is an EV wallbox, use the EV charger guide. If the defined product is gas appliance work, use the gas engineer guide. Come back here for comfort cooling, splits, multi-splits, ducted, cassette and VRF invoicing.

How this differs from heat pump, EV charger, gas engineer and electrician guides

Do not duplicate an entire heat pump guide here. Mentions of Notice 708/6 are contrast only: heat pumps may qualify; ordinary comfort cooling generally does not. Soften and check the live notice.

Three air conditioning jobs, three invoices

These three jobs can use similar kit but need different invoice logic.

A main contractor can be the CIS contractor even when the finished system serves a tenant or homeowner. If the builder engages you, your invoice is to that builder. That contractor-to-subcontractor payment is the one to test. If the householder hires and pays you directly, the householder invoice has no CIS.

Product types: wall split, multi-split, ducted, VRF, cassette, portable caution

Name the product so a QS, householder or future buyer can see what was actually installed.

Commercial versus domestic on the description

What air conditioning work belongs on the invoice

Name the work so a QS, householder or future buyer can see what was actually installed.

Weak versus usable descriptions

What a UK air conditioning invoice must include

UK invoices for trades follow the same core fields whether you are fitting a domestic wall split or a commercial VRF package. If you are VAT-registered, the invoice becomes a VAT invoice with extra fields. Use our how to invoice a client guide for the wider pattern.

Checklist you can tick in the van

• Customer type confirmed (householder vs contractor)

• Site / plot / PO / floor on every stage invoice

• System type named (wall split / multi-split / ducted / cassette / VRF)

• Indoor head count and locations named

• Install vs repair/maintenance narrative clear for CIS

• Labour and materials split if CIS

• Materials at direct cost only for CIS materials block

• Free-issue outdoor unit from main contractor not claimed as your materials

• Refrigerant charge at direct cost if you paid for it

• Deposit / stage / retention clearly labelled

• Snag list referenced, not buried in a vague "final account"

• Payment terms and bank details present

• No invented Notice 708/6 zero-rate on ordinary AC

• Invoice does not pretend to be F-Gas / REFCOM / Building Control / electrical certificate

Copy-paste air conditioning invoice fields

Use this block as a starting structure (replace figures with your contract amounts):

Invoice number: INV-AC-2026-0042
Invoice date: 10 September 2026
Supplier: [Your trading name], [address], [phone], [email]
UTR: [if CIS subcontractor]
VAT number: [if registered]
Customer: [Householder name OR contractor company]
Site: [address / plot / floor / PO]
Payment terms: 14 days from invoice date

Line 1 - Labour: First fix copper pipe, condensate and dedicated isolator, [address]
Line 2 - Materials (direct cost): Outdoor unit, indoor wall head, copper, insulation, brackets, condensate fittings
Line 3 - Labour: Second fix hang, vacuum, refrigerant charge labour, commission and handover
Line 4 - Materials (direct cost): Refrigerant charge / top-up for this job
Line 5 - Variation (if any): Extra indoor head, bedroom 2

Net labour subtotal: £...
Net materials subtotal: £...
VAT @ 20% (if applicable): £...
CIS deduction @ 20% / 30% on labour only (if applicable): £...
Amount due: £...

For deposits, issue a separate deposit invoice before ordering outdoor units and indoor heads, then credit or allocate that deposit on the stage / final invoice.

Sole trader versus limited company

Do not put a personal name only when the contract is with your limited company. Do not invent a VAT number. If you are approaching the £90,000 VAT registration threshold, plan registration timing carefully - this guide is not registration advice. Older posts that still say £85,000 as the current threshold are outdated for current wording; always confirm on GOV.UK.

Labour versus materials: outdoor unit, heads, pipe, condensate, electrics, refrigerant

On CIS jobs, the contractor deducts from the labour element. Materials at direct cost (what you paid for this job) are not deducted. Mark-up sits in the labour base. Free-issue outdoor units or indoor heads from the main contractor are not your materials.

For materials at direct cost, see CISR15060 / CISR15090.

Sample line items table (illustrative)

All money figures you later insert are illustrative contract amounts, not a national price guide.

CIS deep dive: air conditioning under CISR14090

For contractor-paid work, start with CISR14090: building service systems - installation of systems of air-conditioning (alongside heating, lighting, power and other building services) under FA04/S74(2)(c). Soften absolute claims - InvoiceAdept does not decide whether a particular contract is in or out. The facts of the contract matter.

Key nuances (paraphrased carefully from HMRC manuals):

• Installation of systems of air-conditioning is typically within CIS when a contractor pays you.

• Repair, maintenance and replacement of parts of an air-conditioning system are generally outside CIS under the CISR14090 framing.

• Alteration or extension of an existing air-conditioning system is generally outside, unless the work is mixed with other construction operations that bring the contract in (CISR14020 / CISR14030).

• A new install or a complete system replacement that is true installation of a system is typically in when contractor-paid.

• Householder-direct contracts: no CIS, because the householder is not a CIS contractor (CISR12030 / public CIS guide).

• Materials at direct cost - CISR15060 / CISR15090. Free-issue outdoor unit is not your materials.

• Supply-only / delivery of units generally outside (CISR14220) unless mixed with install.

• Related fabric openings, plant-room works or making-good packages can still touch CISR14100 / CISR14240, but lead with CISR14090 for the air-conditioning system itself.

Rates after verification: 20% if registered net, 30% if not verified, 0% with gross payment status. Show UTR, labour, materials, rate, deduction and net payable. That printout is not a CIS300 - the contractor files it. InvoiceAdept does not file CIS300.

Deemed contractors (non-construction businesses) use a construction-spend test of more than £3 million in the 12 months since the first payment - not a £1 million myth. Mainstream construction businesses register when they pay subcontractors for construction work. See GOV.UK CIS.

Install versus repair on the same customer relationship

If your quote started as repair and grew into a full system replacement under the same commercial relationship, revisit CIS before the next invoice. Soften: manuals are guidance; contract facts and advice from your accountant or CIS specialist still matter.

VAT: ordinary comfort cooling is usually 20%, not Notice 708/6 zero-rate

This is the section that differs most from the heat pump sister page. Read it slowly.

If you are not VAT-registered, do not charge VAT. If you are registered, ordinary comfort cooling / air conditioning installs are usually standard-rated at 20%. Soften: InvoiceAdept does not decide VAT rates; check live GOV.UK notices and take advice when unsure.

Do not claim Notice 708/6 zero-rate for ordinary AC

VAT Notice 708/6 sets temporary zero-rate rules for installations of listed energy-saving materials and certain heating equipment (including heat pumps) in residential accommodation and relevant charitable buildings when conditions are met. Ordinary air conditioning / comfort cooling is not treated in this guide as a Notice 708/6 zero-rated heat-pump install. Do not invent 0% for a domestic wall split "because cooling saves energy" or because a heat pump brochure sat in the same van. Soften carefully: if a product is genuinely a qualifying heat pump under the notice, use the heat pump invoice template analysis - do not stretch that analysis onto ordinary comfort cooling.

Practical starting points (always soften)

The VAT registration threshold used in this guide is £90,000. Never present £85,000 as the current threshold. Older articles mentioning £85,000 are outdated for current threshold wording - confirm on GOV.UK before registration decisions.

Never tell a householder their comfort-cooling multi-split is "VAT free because energy-saving materials are zero-rated" without checking the notice lists. Never reverse-charge a private individual.

Supply-only versus supply-and-install

If you quote supply-only and later add install under the same commercial relationship, revisit both CIS and VAT before the next invoice.

Domestic reverse charge note for contractor-paid AC installs

Domestic reverse charge is a VAT rule between eligible VAT-registered construction businesses. It is not CIS and it is not a householder rule. When it applies to a standard-rated construction supply, you show VAT but the customer accounts for it - you do not collect the VAT as cash on that invoice. Full pattern: domestic reverse charge invoice UK.

Critical for air conditioning: most ordinary comfort-cooling installs that are standard-rated may still need reverse-charge analysis only when the CIS / VAT reverse-charge tests between businesses are actually met. Soften and get advice when unsure. If the customer is a private householder, reverse charge does not apply anyway. Never reverse-charge a householder.

Deposits and staged payments for air conditioning packages

A same-day minor controller swap can be one invoice. A multi-split with three heads, long pipe runs and electrics - or a commercial VRF - is not.

1. Survey / design: heat load / siting notes and proposal if billed as a stage. 2. Equipment order deposit: before you order the outdoor unit and indoor heads. Invoice when you take it and state the percentage or fixed sum. See deposit invoice template. 3. First fix pipe / electrics: copper routes, condensate, cable and isolator ready for plant. 4. Second fix heads / commission: outdoor and indoor hung, vacuum, charge, commission, user handover. 5. Snag / handover: agreed snags closed, balance less any agreed retention, plus variations approved in writing.

Retention is not a deposit. Deposit is money you take before or during. Retention is money held after completion against snagging. Show full value, retention withheld and release date, then invoice retention when it falls due. A deposit you receive is a VAT tax point for that amount on the day it lands if you are registered - apply the correct rate (usually 20% for ordinary AC).

F-Gas, REFCOM, Building Control and electrical certificates - the invoice is not those

Keep compliance paperwork separate from the money document. The invoice records what you charged; it does not replace statutory or scheme certificates.

Worked examples A-D

Figures are ILLUSTRATIVE arithmetic only, not quotes, not UK average prices, not F-Gas fee amounts, and not a price list. Clearly labelled illustrative - not market rates.

Example A - Householder wall-split install (no CIS, standard-rated VAT)

ILLUSTRATIVE. Assumes VAT-registered installer and a typical domestic comfort-cooling install on an existing dwelling (not Notice 708/6; not claimed as heat-pump zero rate).

Do not force Notice 708/6 0% onto this example.

Example B - Householder multi-split with deposit and stages (no CIS)

ILLUSTRATIVE. Householder; stages; VAT shown at 20% as an illustrative ordinary AC assumption.

Example C - Contractor-paid new AC installs on plots (verified 20% CIS)

ILLUSTRATIVE only. Verified subcontractor at 20%. Treat figures as VAT-exclusive for clarity. Assumes installation of air-conditioning systems (CISR14090 in scope as a starting analysis), not a pure repair, and not a householder-direct contract.

Do not claim free-issue outdoor units as materials. Soften VAT on the contractor invoice separately - usually standard-rated for ordinary AC, or reverse charge only where tests are met on standard-rated lines.

Example D - Repair / maintenance call-out vs materials-only delivery

If Example D's "repair" later becomes a full system replacement under the same contractor relationship, revisit CISR14090 before treating the next invoice as outside CIS.

Free vs Pro vs Pro+ for air conditioning installers

Use the invoice generator to raise a first draft, then keep stage numbers and deposit credits tidy across the job.

What the invoice is not

Late payment: contractor debts are not consumer debts

Checked on 10 September 2026: Bank of England Bank Rate is 3.75% (held 30 July 2026; next MPC decision due 17 September 2026). For eligible business-to-business debts, statutory interest under the Late Payment of Commercial Debts framework is Bank Rate + 8% - currently 11.75% simple interest - plus fixed compensation of £40 / £70 / £100 per late invoice depending on debt size. Use the six-month reference date rule (rate in force on the preceding 31 December or 30 June). This statutory route does not automatically apply to private homeowners. Soften consumer vs commercial. See late payment rights for UK tradespeople and GOV.UK late commercial payments. InvoiceAdept does not file Money Claim Online or court claims.

Making Tax Digital: records, not filing

Good air conditioning invoices feed your sales records and (if registered) your VAT records. InvoiceAdept helps you create numbered invoices and keep amounts clear. It does not file Making Tax Digital updates, VAT returns, CIS300 or Self Assessment to HMRC. Keep delivery notes, refrigerant purchase tickets and free-issue notes so CIS materials evidence stays clean.

How InvoiceAdept helps air conditioning installers

Quote versus invoice versus retention on contractor packages

Do not bury retention inside a vague "final account" with no release date. Do not treat a quote PDF as the tax invoice.

Mistakes that bounce air conditioning invoices

Variations that commonly appear on air conditioning jobs

Approve variations in writing before you hang the extra head. Silent extras are how disputes start.

Retention on contractor air conditioning packages

How to describe AC plant without sounding like a brochure

Snagging and practical completion on AC installs

Snag lists belong on the handover pack and as references on the final invoice ("snags S1-S4 closed 10 Sep 2026"), not as a substitute for a clear stage description. Practical completion on contractor packages should match the main contract language where you have it. Soften: InvoiceAdept does not decide contractual PC dates.

Checklist before you hit send

• Bill-to name matches who actually pays

• Site / plot / floor / PO present

• System type and head count present

• Install vs repair narrative matches the work done

• Deposit credits allocated

• CIS block only when contractor-paid and in scope

• Materials at direct cost; free-issue excluded

• VAT 20% default for ordinary AC if registered - no invented 708/6 0%

• No reverse charge on householders

• Bank details / card link / due date present

• Certificates referenced separately, not faked as the invoice

Payment terms, applications and cash flow for multi-day AC jobs

For late commercial debts between businesses, statutory interest can be Bank of England Base Rate + 8% plus a fixed sum where the Late Payment of Commercial Debts rules apply. Do not assume the same regime against a consumer householder. Keep commission sheets, delivery notes and snag sign-offs - they support applications more than a vague "AC complete" email.

Record-keeping for CIS, VAT and Self Assessment

Good air conditioning invoices feed three record sets: your sales book, your CIS labour/materials evidence, and (if registered) your VAT records.

InvoiceAdept stores invoice records you create; it does not replace your accountant, does not file CIS300 or VAT returns, and does not submit Self Assessment. Use it to keep numbers clean, then let filing tools or your accountant talk to HMRC.

Working beside electricians, builders and heat pump crews

More worked detail: CIS materials evidence

Keep merchant invoices and delivery notes that match the outdoor unit serial / model cues and indoor head counts on the stage invoice. If the main contractor free-issues plant, file their free-issue note and show labour only on your CIS invoice. Refrigerant at direct cost needs a ticket - do not invent a materials line from a mark-up wish.

More worked detail: householder communication channel

Householders often approve deposits and stage photos on WhatsApp. Pro includes WhatsApp send so the invoice lands in the same thread as the "heads arrived" message. Still keep the PDF fields complete: system type, head count, deposit credit and due date. Soften: messaging is delivery, not a substitute for a proper invoice number.

FAQ

What should a UK air conditioning invoice include?

Your business name and contact details, the customer name, a unique sequential invoice number, the invoice date, a clear description (system type, head count, rooms/zones, stage, site/plot), amounts due, and payment terms. If VAT-registered, add your VAT number, net amounts, VAT rates and VAT totals. If billing a CIS contractor for an in-scope install, show labour, materials at direct cost, deduction rate and net payable.

Is air conditioning installation inside CIS?

Installation of systems of air-conditioning is typically within CIS when a contractor pays you - lead with CISR14090. Soften absolute claims - contract facts matter. InvoiceAdept does not decide your CIS status.

Are AC repairs and maintenance inside CIS?

Under the CISR14090 framing, repair, maintenance and replacement of parts of an air-conditioning system are generally outside CIS. Alteration or extension of an existing system is generally outside unless mixed with other construction operations (CISR14020 / CISR14030). Soften and test facts.

Does a householder deduct CIS from an air conditioning installer?

No. A private householder paying for work on their own home is not a CIS contractor (CISR12030 / public CIS guide). CIS sits on contractor-to-subcontractor construction payments, not ordinary domestic householder invoices.

How do CIS deductions work on outdoor units, heads and labour?

Deductions apply to the labour element. Materials you supply should be shown at direct cost and are not subject to CIS deduction. Free-issue materials from the main contractor are not your materials. See CISR15060 / CISR15090.

How should I invoice a multi-split in stages?

Common pattern: survey/design if billed, deposit before ordering outdoor unit and heads, stage for first fix pipe/electrics, stage for second fix hang/commission, then snag/retention release if the contract holds retention. Give each stage its own invoice number and the same site reference. See the deposit invoice template.

Do I charge VAT on a domestic air conditioning invoice?

If you are not VAT-registered, no VAT. If you are VAT-registered, ordinary comfort cooling / air conditioning on an existing dwelling is usually standard-rated at 20%. Do not invent Notice 708/6 zero-rate for ordinary AC. Heat pumps can have a different Notice 708/6 analysis - see the heat pump guide and the live notice.

Can I zero-rate air conditioning under Notice 708/6?

This guide's starting point is no for ordinary comfort cooling / air conditioning. Do not claim Notice 708/6 zero-rate for ordinary AC. Soften: check the live notice; InvoiceAdept does not decide VAT rates. If the product is a qualifying heat pump, use the heat pump sister page.

When does domestic reverse charge apply to an AC installer?

When you make an eligible VAT-registered construction supply to another VAT-registered customer in the construction supply chain under the domestic reverse charge rules. It does not apply to private householders and does not apply to zero-rated supplies. See domestic reverse charge invoice UK.

What if I only supply outdoor units or portable AC with no installation?

Manufacture and delivery of materials is generally outside CIS (CISR14220). VAT on supply-only is usually standard-rated if you are registered. If you later add installation under the same contract, revisit mixed-contract CIS rules (CISR14020 / CISR14030).

What is the deemed contractor threshold?

Deemed contractors use a construction-spend test of more than £3 million in the relevant period - never invent a £1 million figure. See the public CIS guide.

Is the VAT registration threshold still £90,000?

This guide uses the current UK VAT registration threshold of £90,000. Always confirm on GOV.UK before making registration decisions. Older articles mentioning £85,000 are outdated for current threshold wording.

Can I charge statutory late-payment interest on a householder AC job?

Statutory B2B late payment interest (Bank Rate + 8% plus fixed sums, when rules apply) is aimed at business-to-business debts. Householder consumer contracts are different. Use clear contractual terms and see late payment rights. As at this guide's check, Bank Rate 3.75% held 30 July 2026 implies statutory 11.75% where B2B rules apply; next MPC context 17 September 2026.

Does InvoiceAdept file CIS, VAT or Making Tax Digital to HMRC?

No. InvoiceAdept helps you create professional invoices and records. It does not file CIS300, VAT returns, MTD updates or Self Assessment to HMRC.

Is the invoice an F-Gas or electrical certificate?

No. Keep F-Gas, REFCOM, Building Control and electrical certificates in their own packs. The invoice is the money document.

How does InvoiceAdept pricing work for AC installers?

Free: £0 for five invoices per month. Pro: £7.99 excl VAT with WhatsApp send. Pro+: £12.99 excl VAT with CIS-focused features. Stripe's own fees apply; InvoiceAdept adds no platform fee.

Do I need different invoices for VRF versus a single wall split?

Same field pattern, different description detail. VRF needs outdoor module / indoor count / zone narrative; a wall split needs one outdoor + one head and room. CIS/VAT logic still follows who pays and install vs repair.

Related guides

• Heat pump invoice template UK

• EV charger invoice template UK

• Gas engineer invoice template UK

• Electrician invoice template UK

• Solar panel invoice template UK

• Insulation invoice template UK

• Builder invoice template UK

• Deposit invoice template UK

• Domestic reverse charge invoice UK

• How to invoice a client UK tradesperson

• Late payment rights UK tradespeople

About this guide

Last reviewed 10 September 2026. General information for UK air conditioning and refrigeration installers on invoicing patterns, CIS framing under CISR14090, VAT caution versus Notice 708/6 heat-pump analysis, deposits, stages and certificate contrasts. Not tax, legal, F-Gas, Building Regulations or electrical advice. InvoiceAdept does not decide CIS or VAT status and does not file CIS300, VAT returns, Making Tax Digital updates or Self Assessment to HMRC. InvoiceAdept is a product of Tech Me Today Ltd, Companies House 15917255, ICO ZB944663.