How to invoice variation orders and extras UK (2026)
How to invoice variation orders and extras UK, short answer: confirm the extra in writing first, code it (V01, V02…), put it on own lines, and invoice when the work is done or on the next stage bill. Who pays sets the paper trail: householder WhatsApp/email is writing; main-contractor work usually wants a numbered VO against the PO. CIS may apply when a CIS contractor pays you for construction operations — soften with HMRC’s CIS overview and your accountant. A private householder on their own home is usually not CIS. If you are VAT-registered (threshold £90,000), show VAT correctly; if not, do not charge VAT.
This page is the process for extras — not a second invoice template. For field lists on the PDF, use trade templates such as electrician, plumber, roofer, builder or carpenter. Sister pages: deposit, progress payment, retention. A dedicated variation-invoice-template-uk page may follow — until then, stay here for process and open a trade template for fields. Figures are illustrative only. Need the PDF now? Open the free invoice generator (Free: 5 invoices; Pro £7.99 / Pro+ £12.99).
Who pays for the extra (CIS and VAT first)
Who pays you | Typical extra | CIS? | VAT if registered |
|---|---|---|---|
Private householder | Saturday add-on on their own home | Usually no — never treat them as CIS contractor | Often 20% on ordinary domestic works — soften Notice 708; do not invent 0% |
Main contractor / CIS contractor | Numbered VO against PO / package | May be in CIS base when ops are in scope — soften | Normal VAT, or reverse charge only when contractor tests met — never on a householder |
Landlord / agent | Extra sockets / finishes on a let | Depends whether the payer is a CIS contractor for construction ops | Show net / VAT / gross if registered |
CIS rates sit with the contractor when CIS applies. InvoiceAdept does not decide status and does not file CIS300, VAT returns, MTD or Self Assessment. VAT threshold is £90,000.
What counts as a variation (and what does not)
Item | Is it a variation / extra? | Use instead |
|---|---|---|
Client-asked change to scope with a new price | Yes | This process + trade template fields |
Snagging / defects under original scope | Usually no | Fix under the original job — not a VO line |
Retention release | No | |
Deposit / advance | No | |
Interim stage for work already scheduled | No (unless the stage itself changed) |
Confirm in writing before you start
Price labour and materials separately — especially if a contractor will pay you under CIS. Send the price in writing (WhatsApp, email, or a short PDF note). Photo of the rotten timber or blank wall helps. Keep the thread with the job folder.
Payer | What “in writing” usually looks like |
|---|---|
Householder | WhatsApp / email with clear scope and price — signed PDF is nice, not required for every Saturday extra |
Main contractor / QS | Numbered VO against PO; follow their accounts process |
If they refuse to confirm: do not do the extra. Starting without a yes is arguing, not invoicing.
How to invoice the extra (must-include cues)
Field / cue | Why it matters |
|---|---|
Own coded lines (V01, V02…) | Never silently inflate the original package lump |
Labour and materials split | CIS and VAT need the split when a contractor pays |
Reference to chat / VO / date | AP and householders can match approval |
Same invoice number as that stage — or a separate extras invoice | Never invent a second live number for the original scope |
Site / job / PO refs | Helps main-contractor AP |
VAT / CIS narrative only when due | Omit CIS on true householder PDFs |
Legal baseline: GOV.UK — what invoices must include. Field lists live on the trade templates, not here.
Copy-paste extras example (illustrative)
Scenario A — householder: spare bedroom wallpaper, WhatsApp yes 12 Aug 2026. Labour £220, materials £85. Not VAT-registered. No CIS.
Line | Net |
|---|---|
V01 — Spare bedroom wallpaper, labour, WhatsApp 12 Aug 2026 | £220.00 |
V01 — Spare bedroom wallpaper, materials | £85.00 |
Amount payable | £305.00 |
Scenario B — main contractor (illustrative): six double sockets, labour £360, materials £94 evidenced. CIS verified 20%. Reverse charge may apply between eligible parties — never on a householder. Invoice gross labour; they withhold from labour.
CIS and VAT on extras
Topic | Practical rule |
|---|---|
Householder own-home extra | Usually no CIS; never reverse-charge them |
CIS contractor construction ops | Extra labour may be in CIS base; evidenced materials may sit outside labour base if accepted |
One lump “extras £800” | Avoid — invites CIS on materials too |
VAT threshold | £90,000 |
Deemed contractor | £3 million construction-spend framing — not £1 million |
Deposit on an extra | If VAT-registered, receipt can be a tax point — soften with accountant |
InvoiceAdept | Does not file CIS300, VAT, MTD or Self Assessment |
Late extras, retention and deposits
Treat late extras the same as early ones: confirm, price, get a yes, then start — or say no. Say if the extra moves practical completion or retention release. Retention is holdback already earned; a deposit is an advance. Do not label either as a “variation” on the PDF.
Common mistakes
Mistake | Fix |
|---|---|
Starting without a written yes | Confirm price and scope first |
One lump extras line on a CIS job | Split labour and materials |
CIS / reverse charge on a householder extra | Remove those narratives |
Silently bumping the original package | Own V0x lines |
Calling retention or deposit a variation | Use retention / deposit sisters |
Assuming the app files MTD / VAT / CIS300 | InvoiceAdept does not file |
Frequently asked questions
Do I always need a signed JCT-style VO?
No. Main-contractor / PO work usually wants a numbered VO. Domestic WhatsApp or email with a clear price often counts as writing — keep the thread.
Same stage invoice or a separate extras invoice?
Either. Own coded lines on the next stage or a same-day variation invoice are fine. Never a second live number for the original scope.
Does CIS always apply to extras?
No. CIS may apply when a CIS contractor pays you for construction operations. Householders on their own home are usually outside CIS.
What VAT threshold should I use in 2026?
£90,000. Soften registration with your accountant. Extras you invoice count toward taxable turnover.
Is snagging a variation?
Usually no. Snagging is defects under the original scope. Retention is holdback; deposit is an advance.
Where do I get the PDF field list?
Open the relevant trade template (electrician, plumber, roofer, builder, carpenter). This page is the extras process.
Does InvoiceAdept file CIS, VAT or MTD?
No. It stores digital invoice records. It does not send CIS300, VAT returns, MTD updates or Self Assessment to HMRC.
Where can I build the PDF quickly?
Use the InvoiceAdept free invoice generator — Free covers 5 invoices; Pro is £7.99 and Pro+ £12.99 when you need more.
Next step: invoice the extra cleanly
Confirm in writing, code the lines, keep householder vs contractor facts straight, show CIS only when due, and show VAT only if registered (£90,000 threshold). Open the free invoice generator, paste the V0x shape, and send. InvoiceAdept does not file CIS300, VAT returns, MTD or Self Assessment for you.
Last reviewed: 17 September 2026.
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