Quote vs invoice vs variation note: a plain guide for NI trades
Most payment arguments in the trades come down to paperwork: a price that was never written down, extra work agreed in a quick chat, an invoice that doesn't match the quote. Four simple documents stop almost all of them. Here's what each one does and what goes on it.
Updated 9 October 2026 · Belfast Desk Kit
The four documents at a glance
| Document | When | What it does |
|---|---|---|
| Quote | Before the job | Sets out the work and the fixed price, for the customer to accept |
| Deposit request | When the quote is accepted | Asks for money up front, usually for materials |
| Variation note | During the job | Records extra or changed work and its price, agreed before you do it |
| Invoice | When the job (or a stage) is done | Asks for payment and is your record for tax |
1. The quote
A quote is a fixed price for a defined job. Once accepted, it forms part of the contract. A good quote includes your details, the customer's details and job address, a quote number and date, the work broken into lines, what's not included, the total (with VAT shown if you're registered), how long the price is valid, timings and payment terms.
The "not included" line matters most. Making good, skips, decorating and certification are classic sources of argument. DeskKit Quotes has a full guide on how to write a quote for a job, and one on quote vs estimate if you can't give a fixed price.
If you agree the job with a consumer at their home or at a distance, they usually have 14 days to cancel under the Consumer Contracts Regulations, and you must tell them. Put the cancellation information with the quote.
2. The deposit request
If you need to buy materials before starting, ask for a deposit when the quote is accepted. Say how much, what it covers, how to pay and that it comes off the final bill. Keep it proportionate. Under UK consumer law, any deposit you keep if a customer cancels should reflect what you actually lose. Here's more on how much deposit to ask for.
3. The variation note
Jobs change. The customer wants an extra socket, you find rotten joists, the tiles they chose are discontinued. A variation note records the change before you do the work:
VARIATION No. 2 to quote Q-1042 | Date: 20 October 2026
Change: replace two rotten joists found under bathroom floor (photos sent by WhatsApp).
Extra cost: £240 (materials £90, labour £150). Extra time: half a day.
Agreed by customer: name, date (or a reply to this message saying "agreed").
A text or WhatsApp reply of "yes, go ahead" is far better than nothing. Number your variations so they're easy to add to the invoice.
4. The invoice
An invoice asks for payment and is the record your accountant and HMRC rely on. GOV.UK lists what an invoice must include:
- a unique invoice number (number them in order)
- your business name, address and contact details, and as a sole trader your own name
- the customer's name or company name and address
- a clear description of what you're charging for
- the date the work was done (supply date) and the date of the invoice
- the amounts, any VAT, and the total owed
Also add the quote number, any variation numbers, deposits already paid, the balance due, the payment due date and your bank details. If you're VAT registered and invoicing another VAT-registered business, you need a full VAT invoice.
VAT and the construction reverse charge
You must register for VAT once your VAT-taxable turnover goes over the threshold, currently £90,000 (check GOV.UK). If you're VAT registered and work as a subcontractor under the Construction Industry Scheme for another VAT-registered builder, the domestic reverse charge may apply, which changes what goes on the invoice. Ask your accountant if you're unsure.
Keep your records
Keep copies of quotes, variations and invoices together for each job. If you're self-employed, GOV.UK says to keep business records for at least 5 years after the 31 January submission deadline of the relevant tax year.
Templates
If you'd rather work in Excel and Word, the quote and invoice pack for NI trades (£12) includes a quote, invoice, deposit request and variation note, with a VAT on/off switch.
Do all four from your phone
DeskKit Quotes sends quotes your customers accept online, asks for a deposit, and turns the accepted quote into a numbered invoice in one tap, with a CSV export for your accountant. Free for 14 days, no card needed.
Frequently asked questions
What is the difference between a quote and an invoice?
A quote is sent before the job and sets the price for the customer to accept. An invoice is sent after the work, or a stage of it, and asks for payment. The invoice should match the quote plus any agreed variations.
What is a variation note?
A short written record of extra or changed work and its price, agreed with the customer before you do it. It stops arguments about the final bill.
Does a sole trader invoice need my own name on it?
Yes. GOV.UK says sole trader invoices must include your name and any business name you use, plus an address where legal documents can be delivered if you use a business name.
More guides
- A weekly admin checklist for small businesses in Northern Ireland
- How to fix your Google Business Profile in Belfast, step by step
- All guides
General information, not legal, tax or professional advice. Rules change, so check the official sources linked above before you rely on them.