Freelancing in the UK: Tax, Rates and Operating Models

How to Invoice Correctly as a Freelancer UK

What to include on a freelance invoice, legal requirements, VAT invoices, payment terms, and how to chase late payments. Free invoice checklist.

Self-employment tax and business information is based on current HMRC rules. This is not tax or accounting advice. Consider consulting a qualified accountant for your specific circumstances.

Start here: Freelancing Hub.

Getting your invoices right is essential for maintaining cash flow and staying on the right side of HMRC. This guide covers exactly what to include, how to handle VAT, what payment terms to set, and how to deal with clients who do not pay on time.

What to Include on an Invoice

Mandatory Elements

ElementExample
The word “Invoice”Clearly labelled at the top
Your name or business nameJane Smith / JS Design Ltd
Your address10 High Street, Bristol, BS1 1AA
Client’s name and addressAcme Ltd, 5 Park Road, London, EC1A 1BB
Unique invoice numberINV-2026-001 (sequential)
Invoice date25 March 2026
Description of workWebsite design — homepage and 5 inner pages
Amount due£2,500.00
Payment termsPayment due within 30 days
Payment method and bank detailsSort code, account number, account name

Additional Elements (If Applicable)

ElementWhen needed
VAT number and VAT amountIf you are VAT-registered
Purchase order numberIf the client provided one
Project or job referenceIf agreed with the client
Expenses breakdownIf claiming reimbursable expenses
Late payment termsIf you want to enforce interest on late payments
Company registration numberIf you trade as a limited company

Invoice Numbering

Use a consistent, sequential numbering system. HMRC requires invoice numbers to be unique and sequential (no gaps without explanation).

SystemExampleNotes
Simple sequential001, 002, 003Works for low volume
Year-prefixed2026-001, 2026-002Easy to identify the tax year
Client-codedACME-001, ACME-002Useful if you have few clients
Date-basedINV-20260325-01Clear when invoice was issued

VAT Invoices

If You Are Not VAT-Registered

  • Do not show VAT on your invoices
  • Do not charge VAT to clients
  • Show the total amount due as a single figure

If You Are VAT-Registered

Your invoice must additionally include:

VAT requirementDetails
Your VAT registration numbere.g. GB 123 4567 89
The net amount (before VAT)£2,500.00
The VAT rate20%
The VAT amount£500.00
The gross total (including VAT)£3,000.00
Tax point (date of supply)The date the work was completed or the invoice date

Simplified VAT Invoice

If the total including VAT is £250 or less, you can issue a simplified VAT invoice. This only needs:

  • Your name, address, and VAT number
  • Date of supply
  • Description of goods or services
  • Total amount including VAT
  • The VAT rate

Payment Terms

Common Options

TermWhen payment is dueBest for
Due on receiptImmediatelySmall jobs, one-off clients
Net 7Within 7 daysUrgent or small invoices
Net 14Within 14 daysFreelancers (recommended default)
Net 30Within 30 daysCorporate clients (industry standard)
Net 60Within 60 daysLarge companies (push back if possible)
50% deposit + 50% on completionSplit paymentNew clients, large projects
Milestone paymentsAgreed stagesLong-term projects

Late Payment Interest

Under the Late Payment of Commercial Debts (Interest) Act 1998, you are entitled to charge:

ChargeAmount
Interest rate8% + Bank of England base rate (per year, calculated daily)
Compensation£40 (invoices up to £999.99)
Compensation£70 (invoices £1,000–£9,999.99)
Compensation£100 (invoices £10,000+)

You do not need to state this on your invoice for the right to apply, but including it makes enforcement easier.

Chasing Late Payments

Process

TimingAction
Day before dueSend a friendly reminder email
Due date + 1 daySend a polite follow-up: “Just checking this has been received”
Due date + 7 daysSend a firmer reminder with the invoice attached
Due date + 14 daysPhone the client and follow up in writing
Due date + 21 daysFormal letter warning of late payment interest and further action
Due date + 30 daysIssue a letter before action (pre-legal step)
Due date + 45 daysConsider small claims court (Money Claim Online for under £10,000)

Tips for Getting Paid Faster

StrategyHow it helps
Invoice immediately on completionDo not delay — invoice the day you finish
Offer multiple payment methodsBank transfer, card, PayPal — make it easy
Set shorter payment terms14 days instead of 30 for small clients
Request deposits25–50% upfront, especially for new clients
Use accounting softwareAutomated reminders save you chasing manually
Build payment into contractsWritten agreement before work starts

Invoicing Software

SoftwareCostBest for
FreeAgentFrom £12/monthFreelancers and small businesses
XeroFrom £15/monthGrowing businesses
QuickBooksFrom £12/monthSelf-employed and small businesses
WaveFreeBudget-conscious freelancers
Tide (built-in)Free with Tide accountSimple invoicing
CoconutFrom £8/monthFreelancers who want tax tracking

Most accounting software generates professional invoices, tracks payments, and sends automatic reminders. This is worth the monthly cost for the time it saves.

Record Keeping

RequirementDetails
Keep copies of all invoicesDigital copies are fine
Retention periodAt least 5 years after the 31 January Self Assessment deadline
FormatPDF, paper, or within accounting software
Expenses receiptsKeep receipts for any expenses claimed on invoices

Related guides:

Sources

  1. GOV.UK — Late commercial payments