How to Invoice as
Self-Employed in the UK
A plain-English guide to invoicing your clients correctly as a self-employed person or sole trader — from registering with HMRC to chasing late payments and keeping records for Self Assessment.
Create Your First Invoice FreeNo credit card required. Free plan available.
Step-by-step: invoicing as self-employed
Register as self-employed with HMRC
Before you can invoice clients, you need to register as self-employed. Do this via the HMRC website. You must register by 5 October in your second year of trading, but registering immediately is better. HMRC will send you a Unique Taxpayer Reference (UTR) — keep this safe.
Agree the work and price before you start
Always agree the scope, deliverables, and price in writing before beginning work — even a simple email confirmation is enough. This makes invoicing straightforward and protects you if a client disputes a charge later.
Create your invoice
Once the work is complete (or at the agreed billing point), create your invoice with all the required information. Use QuickBill to create a professional PDF invoice in under two minutes.
Send it promptly
Send the invoice as soon as the work is done. The payment clock only starts when the client receives your invoice. Delaying invoicing is the single most common reason self-employed people get paid late.
Follow up if payment is late
If payment has not arrived by the due date, send a polite reminder the next day. QuickBill can send these automatically. If the client still does not pay, you are legally entitled to charge interest and debt recovery costs under the Late Payment of Commercial Debts Act 1998.
Record it for Self Assessment
Keep a copy of every invoice you send. You will need these when completing your annual Self Assessment tax return. HMRC requires you to keep business records for at least 5 years after the 31 January deadline for the relevant tax year.
What to put on a self-employed invoice
There is no legally required format for a self-employed invoice in the UK (unless you are VAT registered), but including the following will satisfy HMRC and your clients' accounts teams.
Your full name (or business name)
Your address
Invoice number (sequential — e.g. INV-001)
Invoice date
Payment due date (e.g. 30 days from invoice date)
Client name and address
Description of the work or services provided
Amount due (in the correct currency)
Your bank sort code and account number
If you are VAT registered, you must also include your VAT number, the VAT rate applied, and the VAT amount. See our VAT invoice guide →
Invoices and Self Assessment
Every year, self-employed people in the UK must complete a Self Assessment tax return. Your invoices form the basis of your income figures. Here is what HMRC wants to see:
Total income
The sum of all your invoices in the tax year (6 April to 5 April), regardless of whether they have been paid yet.
Allowable expenses
Business costs you can deduct — equipment, software subscriptions, travel, home office proportion, professional fees.
Profit
Income minus allowable expenses. This is what you pay Income Tax and National Insurance on.
Record-keeping reminder: HMRC requires self-employed people to keep business records — including all invoices — for at least 5 years after the 31 January Self Assessment deadline for the relevant tax year. QuickBill stores all your invoices securely so they are always available.
When do I need to start charging VAT?
You must register for VAT when your taxable turnover exceeds £90,000 in any rolling 12-month period. Once registered, you must add VAT to your invoices and issue VAT invoices with additional required fields.
You can also register voluntarily below the threshold — this is worth considering if most of your clients are VAT-registered businesses, as they can reclaim the VAT you charge.
Read our VAT invoice guideFreelance invoice template
Day rates, projects, retainers
UK invoice template
What to include on any UK invoice
Ready to send your first invoice?
QuickBill creates professional invoices in minutes, stores them for your Self Assessment records, and chases late payments automatically.
Create Your First Invoice FreeFree plan available. No credit card required.