How to write a freelance invoice: a step-by-step checklist (with wording to copy)

An invoice is a short document, but a missing number, a vague description or no due date is often why it sits unpaid. Here's how to write and send a normal freelance invoice, step by step: what to check before you invoice, what to put on it, how to number and date it, how to lay out the line items, the payment terms, what to keep, and how to handle deposits and corrections, with an invoice email and reminders you can copy. It works in any country; where an official page sets a rule, we quote it and link it.

The steps, layout and wording are general practice, not a legal standard. The official rules quoted (GOV.UK, HMRC, the CRA and the IRS) were checked against those pages on 2026-10-14. Not written by a lawyer or a tax adviser.

The short answer

• Check what was agreed first: the price, what's being billed now, any deposit already paid, the client's legal name, billing contact and purchase order number.
• Put the basics on every invoice: a unique invoice number, the invoice date, the date of the work, your details and the client's, a clear description, the amounts, any tax, the total and the due date.
• Show how to pay and quote the payment terms you agreed, rather than leaving the client to guess.
• Send it to the right person, as a PDF, with a short email; keep a copy and never reuse a number.
• Fix mistakes with a new document (a credit note or a corrected invoice), not by quietly editing one you've sent.
• Check the local rules. In the UK, GOV.UK lists what an invoice must include. If you're registered for UK VAT or Canada's GST/HST there's more; see our UK VAT invoice and Canada GST/HST invoice guides.

1. Invoice, receipt, quote or proposal?

They're easy to mix up. GOV.UK puts the first difference plainly: "An invoice is not the same as a receipt, which is an acknowledgement of payment." (GOV.UK). The rest is general practice:

A "pro forma" invoice is a preview of an invoice, sent before the work or before a payment; it usually isn't a request to pay. If you mean "please pay this", send a real invoice.

2. Before you invoice

General practice: a few minutes here saves a rejected invoice later.

• The agreement. What price, scope and payment terms did you agree, and is this invoice for all of it, a milestone, a month of hours or a deposit? Any agreed extra work goes on as its own line (see change requests).
• What's already been paid. A deposit or part payment gets credited on this invoice (section eight).
• The client's legal name and billing address, which may differ from the brand you work with day to day.
• The billing contact: often accounts payable, not the person you do the work with. Ask where invoices go.
• A purchase order (PO) number or other reference, if the client uses them. Some clients' accounts teams can't pay an invoice without one.
• The client's own rules: some want invoices uploaded to a supplier portal, a set format, or a supplier form first.
• Tax forms the client needs. A US client may ask for a Form W-9 before they pay you (see our Form W-9 guide).
• Whether you charge a sales tax. Only add VAT, GST/HST or another tax if you're registered for it. Whether you need to register is a separate question: see our UK VAT threshold and Canada GST/HST guides.
• The hours or deliverables behind it, ready in case the client asks (a timesheet or your project tracker).

Our client onboarding checklist collects most of these at the start, so you only ask once.

3. What to put on the invoice

The fields below are what a clear freelance invoice usually shows. The last column says where an official page we read asks for it.

United Kingdom: what GOV.UK says every invoice must include

"Your invoice must include:" (GOV.UK: Invoices – what they must include)

• a unique identification number
• your company name, address and contact information
• the company name and address of the customer you’re invoicing
• a clear description of what you’re charging for
• the date the goods or service were provided (supply date)
• the date of the invoice
• the amount(s) being charged
• VAT amount if applicable
• the total amount owed

"If you're a sole trader, the invoice must also include:"

• your name and any business name being used
• an address where any legal documents can be delivered to you if you are using a business name

For companies: "If your company is a limited company, you must include the full company name as it appears on the certificate of incorporation." And: "You must use VAT invoices if you and your customer are VAT registered." Our UK VAT invoice guide has HMRC's full list. When an invoice is required at all, GOV.UK says: "If you sell a customer a product or a service, you need to give them an invoice (bill) by law if both you and the customer are registered for VAT (a business to business transaction)." (GOV.UK: Invoicing and taking payment from customers).

Canada: GST/HST information on invoices

If you're registered for GST/HST, the CRA's input tax credit chart lists what your invoices need to show so a registered client can claim the tax back. It grows with the size of the sale: under $100, $100 to just under $500, and $500 or more (CRA: Records you need to support your claim).

• Supplier's business or trading name, or an intermediary's (every invoice)
• The invoice date or, if no invoice issued, the date on which the GST/HST is paid or payable (every invoice)
• The total amount paid or payable (every invoice)
• An indication of the total amount of GST/HST charged or that the amount paid or payable for each taxable supply (other than zero-rated supplies) includes the GST/HST at the applicable rate (from $100)
• An indication of the status of each supply where the invoice includes both taxable and exempt supplies (from $100)
• The supplier or intermediary's GST/HST registration number (from $100)
• The buyer's name or trading name or the name of the buyer's authorized agent or representative (from $500)
• A brief description of the property or services (from $500)
• The terms of payment (from $500)

On any receipt or invoice, the CRA also says you must let customers know: if the GST/HST is being applied to their purchases, and if the GST/HST is included in the price or added separately. Our Canada GST/HST invoice guide goes through each item, with where your GST/HST number goes.

United States and elsewhere

We didn't find an IRS page that lists what a freelance invoice must show. The IRS treats invoices as records that back up your income (section seven). State sales-tax rules can apply to some services; we haven't checked them for this page. We haven't checked other countries' invoice rules either: if you're based elsewhere, look up your tax authority's invoice requirements.

4. Invoice numbers and dates

• Use one running sequence and never reuse or skip a number (general practice). A simple count works, or a prefix for the year followed by a count; what matters is that each number is unique and the order is obvious.
• What the rules say: GOV.UK asks for "a unique identification number" on every invoice (GOV.UK). For a full VAT invoice, HMRC asks for "a sequential number based on one or more series which uniquely identifies the document" (HMRC: VAT Notice). The CRA's chart has no invoice-number row, but a number is still how you and your client find the invoice later.
• Don't delete a sent invoice. If one was wrong, cancel or reduce it with a credit note, then issue a new invoice with a new number (section eight). Gaps and duplicates are hard to explain later.
• Invoice date vs date of the work. Show both if they differ, for example a month of work invoiced at the start of the next month. GOV.UK lists both dates.
• The due date. Write the actual date, not just the terms, so there's nothing to work out.
• Invoice promptly once the work is delivered or a milestone is reached, as agreed (general practice).
• In Canada, the invoice date matters for GST/HST: "The invoice date will determine when you need to report and remit (pay) the GST/HST you charge. Your GST/HST return for the reporting period that covers the invoice date should include the GST/HST you have charged, whether or not you have received payment." (CRA).
• UK VAT: HMRC says you normally issue a VAT invoice within 30 days of the tax point (see our UK VAT invoice guide).

5. Line items, tax and the total

One line per thing you're charging for, described the way your client thinks about it. Common kinds of line (general practice):

Then, in this order: subtotal, any tax on its own line with its name and rate, the total, any deposit or payments already received, and the balance due. State the currency once, near the total, if you bill abroad.

• Tax lines: only for a tax you're registered to charge. In Canada the CRA says you have to show: the GST/HST rate that applies to the supply; and the amount paid or payable and the GST/HST amount as separate lines or a clear statement that the total amount paid or payable includes GST/HST. "If HST applies, show the total HST rate. Do not show the federal and provincial parts separately." (CRA: Receipts and invoices). In the UK, GOV.UK's list includes the "VAT amount if applicable".
• Expenses: pass them on only if your agreement allows it, and keep the receipts. How sales taxes treat passed-on expenses varies; we haven't checked it for this page.
• Hours: bill from a log, not from memory. Our free timesheet adds up billable hours by client.

6. Payment terms and how to get paid

• Write the terms you agreed, plus the due date. Our payment terms guide explains "Net" terms, due on receipt, end of month and early-payment discounts, with wording.
• You set them. GOV.UK: "You can set your own payment terms, such as discounts for early payment and payment upfront." And if you don't agree a date: "Unless you agree a payment date, the customer must pay you within 30 days of getting your invoice or the goods or service." (GOV.UK: Payment obligations). Other countries have their own defaults; agree a date so you aren't relying on one.
• Late fees or interest: only what your agreement or the law allows. GOV.UK: "You have the right to charge interest for late payment, but you can choose not to." See our UK late payment interest calculator or, in Canada, getting paid on time.
• How to pay: the method, the details, and the reference to quote (usually the invoice number), so the payment can be matched to the invoice.
• Changing your bank details? Tell clients in a way they can check (for example by phone as well as email), and treat any email asking you to pay into "new" details with the same care (general practice).

7. Sending it, and what to keep

• Send a PDF (it can't be edited by accident and looks the same everywhere) to the billing contact, copying the person you work with if that helps. Use the invoice number in the email subject.
• Use the client's portal or format if they have one, and keep the confirmation.
• Track it: note the date sent and the due date, and check on the due date, not weeks later.
• Keep a copy of every invoice, including cancelled ones and credit notes, with the agreement and any timesheet behind it.

The tax agencies we checked all name sales invoices among the records to keep (read 2026-10-14):

Page dates on the check date: IRS records page 2026-08-03, IRS how-long page 2026-06-30; GOV.UK record pages 2015-01-23; CRA records page 2025-06-17, CRA how-long page 2026-08-03; GOV.UK invoicing pages 2015-08-07; HMRC VAT Notice 2026-06-25; CRA input tax credit page 2026-10-14, CRA charge-and-collect page 2026-04-08.

8. Deposits, part payments and corrections

• Deposit paid earlier? Show the full price on the final invoice, then a line "Less deposit received" with the date and the deposit invoice's number, and the balance due. Our deposits and retainers guide covers deposit invoices and the GST/HST and UK VAT notes.
• Part payment received? Send a receipt for what came in (our receipt generator does part payments) and show the remaining balance on any reminder.
• A mistake on a sent invoice? General practice: issue a credit note (its own number, the date, which invoice it relates to, and the amount credited), then a corrected invoice if needed. Don't edit and resend under the same number.
• UK VAT credit notes have their own rules: HMRC says a valid credit note must, among other things, be issued within 14 days of the refund payment being made to the customer (see our UK VAT invoice guide). We haven't checked the CRA's rules on credit notes for this page.
• Work billed in stages? Say which milestone or period each invoice covers, so the set adds up to the agreed price.

9. Wording to copy

Plain text with [placeholders]. Change anything in square brackets, and delete what doesn't apply.

The invoice email

Subject: Invoice [invoice number] from [your business name] — [project name]

Hi [name],

Please find attached invoice [invoice number] for [what it covers, e.g. the work in (month) / milestone (name)].

Amount due: [total and currency]
Due date: [due date] ([your payment terms])
How to pay: [bank transfer details / payment link / other agreed method]
Your reference: [purchase order number, if they gave you one]

If anything on it doesn't match what you expected, just reply and I'll sort it out.

Thanks,
[your name]
[your business name and contact details]

A friendly reminder (before or on the due date)

Subject: Reminder: invoice [invoice number] due [due date]

Hi [name],

A quick reminder that invoice [invoice number] for [total and currency] is due on [due date]. I've attached it again in case it's easier to have it to hand.

If it's already on its way, thank you, and please ignore this. If there's a problem with it, let me know and I'll fix it.

Thanks,
[your name]

When it's overdue

Subject: Overdue: invoice [invoice number] — [total and currency]

Hi [name],

Invoice [invoice number] for [total and currency] was due on [due date] and I haven't received payment yet. I've attached a copy.

Could you let me know when it will be paid, or who I should contact about it? Payment details: [how to pay].

[Only if your agreement or the law allows it: As set out in our agreement, [your late-payment terms] apply to overdue invoices.]

Thanks,
[your name]

Only mention late fees or interest you're actually entitled to. For Canada-specific wording and interest, see getting paid on time in Canada; for UK business clients, the UK late payment interest calculator.

Lines for the invoice itself

Payment terms: [your terms, e.g. due within (number) days of the invoice date]. Due date: [due date].
Please pay by [bank transfer / payment link / other agreed method] and quote invoice [invoice number] as the reference.
Less deposit received [date of deposit] (deposit invoice [deposit invoice number]): [deposit amount]
Balance due: [total minus deposit and any part payments]
Thank you for your business.

10. The checklist

• Agreed price, scope, terms and what this invoice covers; deposits and part payments noted.
• Client's legal name, billing address, billing contact and any PO number.
• The word "Invoice", a unique number from your sequence, the invoice date and the date of the work.
• Your details (and, for a UK sole trader using a business name, your own name and an address for legal documents).
• Clear line items, subtotal, any tax you're registered for on its own line, total, deposit credited, balance due, currency.
• Payment terms, the due date and how to pay, with the reference to quote.
• Any extra items your tax registration requires (UK VAT, Canada GST/HST: see the guides linked above).
• Checked once more, saved as a PDF, sent to the billing contact with a short email.
• A copy kept with the agreement and timesheet; the due date noted so you follow up on time.

Free tools and kits

• Free invoice generator: fill in a form and print it or save it as a PDF, any currency, with optional tax lines and UK VAT and GST/HST presets (runs in your browser; nothing is saved).
• Free freelance invoice template: the same kind of invoice as a spreadsheet with live formulas.
• Free receipt generator: once the client pays, in full or in part.
• Free timesheet: the billable hours behind an hourly invoice.
• Free quote and estimate generator: agree the price before you invoice it.
• Our paid Freelance Billing Kit by Small Rows (US$12, one-time) builds the invoice from a time log: pick a client and dates and the invoice fills itself in, with a due date from that client's payment terms. It also shows what's paid, part paid, open or overdue, in any currency. It doesn't send invoices, chase clients or decide which tax applies to you.
• Our paid Quote & Proposal Kit by Small Rows (US$12, one-time) covers the step before: a price list, a quote builder, a printable proposal and a log of every quote you send, so the invoice matches what was agreed.
• All three kits together, with the Client & Project Tracker: the All-Kits Bundle by Small Rows (US$24, one-time).

Where the sources differ

We read the pages under Sources on 2026-10-14. A few details to watch:

• Numbers. GOV.UK asks for a unique identification number on every invoice; HMRC asks VAT invoices for a sequential number; the CRA's chart has no number at all. One running sequence satisfies all three.
• Who the list is for. GOV.UK's list applies to every UK invoice. The CRA's chart is about what a GST/HST-registered buyer needs to claim input tax credits, and it grows with the size of the sale.
• Tax clocks. In Canada the invoice date sets when you report the GST/HST; for UK VAT, the tax point does. They aren't the same rule.
• Old but current pages. GOV.UK's invoicing guide shows a date of 2015-08-07; it was live and current on the check date.
• No US list. We found no federal list of what an invoice must show; the IRS pages are about keeping invoices as records.

When to get advice

• you're not sure whether you have to register for, or charge, VAT, GST/HST or a sales tax;
• you bill clients in another country and aren't sure whose tax rules apply;
• a client disputes an invoice, or won't pay, and you're thinking about interest, fees or legal steps;
• you need to cancel or reduce an invoice that included tax;
• you're unsure how long to keep invoices where you're taxed.

Related free resources

• Invoice payment terms explained: "Net" terms, due on receipt, end of month, discounts and wording.
• Freelance deposits and retainers explained: deposit invoices and crediting them on the final invoice.
• What a GST/HST invoice must show (Canada) and what a UK VAT invoice must show.
• Getting paid on time as a freelancer in Canada and the UK late payment interest calculator.
• How to write a freelance proposal: where the price and terms are first agreed.
• Freelance client onboarding checklist: collect billing details before the first invoice.
• Form W-9 for US freelancers: the form a US client may ask for before paying you.
• All free tools.

Sources

Official pages read on 2026-10-14. Check the live page before you rely on it.

• United Kingdom: GOV.UK: Invoicing and taking payment from customers · GOV.UK: Invoices – what they must include · GOV.UK: Payment obligations · HMRC: VAT guide (VAT Notice) · GOV.UK: What records to keep · GOV.UK: How long to keep your records
• Canada: CRA: Input tax credits – records you need to support your claim · CRA: Charge and collect the GST/HST – receipts and invoices · CRA: What are records, who has to keep them · CRA: Where to keep your records, for how long
• United States: IRS: What kind of records should I keep · IRS: How long should I keep records?

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