How to Write an Invoice in the UK (and Get Paid Faster)
- Feb 6
- 4 min read
Cash is the lifeblood of any business. And let’s be honest - being paid on time is what keeps everything moving.
It all starts with your invoices. These are the documents that show what you’ve supplied, how much is owed, and when you expect to be paid (aka: your “bills”).
When your invoices are clear, compliant and easy to pay, you’re far more likely to get paid quickly - and with less chasing. That’s why understanding how to write an invoice in the UK is a real game-changer for small business owners.
Whether you’re a sole trader, limited company or VAT-registered business, your invoices need to:
Look professional
Meet UK legal requirements
Make it simple for customers to pay you
Using accounting software or ready-made invoice templates can make this much easier - saving you time and helping protect your cash flow.
In this guide, we’ll cover everything you need to know about invoicing in the UK, including:
What to Include in an Invoice (UK Requirements)
A standard non-VAT invoice must include the following:
1. The word “Invoice”
This sounds obvious, but it matters. Clearly label the document as an invoice so it’s not confused with a quote, receipt or credit note.
2. A unique invoice number
Every invoice needs its own unique reference. A simple sequential numbering system works best and keeps your records tidy.
You can include letters as well as numbers if you like.
3. Your business name and address
Your invoice must clearly show:
Your trading name
Your business address
Contact details (in case of queries or disputes)
4. Your customer’s name and address
This is standard on most invoices and essential if your customer wants to reclaim the expense.
5. Description of goods or services
List each service or item clearly, ideally on separate lines. The clearer this is, the fewer questions you’ll get later.
6. Date of supply
Also known as the tax point. This is the date the goods or services were supplied and may differ from the invoice date.
7. Invoice date
The date the invoice was created.
8. Individual amounts
Each item or service should show its own price.
9. Total amount payable
The grand total due.
10. Payment terms
For example:
Payment due within 30 days
These should align with your agreed terms and conditions.
11. Purchase order (PO) number
If your customer provides a PO number, include it. A PO forms a legally binding contract and often speeds up payment.
12. How to pay
Make it easy. Include:
Bank details for BACS
Any reference needed
For international payments: IBAN / BIC / SWIFT
Different Types of Invoices
Your invoice requirements vary depending on your business setup.
Sole traders don’t need to include a Unique Taxpayer Reference (UTR)
Limited companies must include their registered details
VAT-registered businesses have additional rules (see below)
Sole Traders and Limited company Invoices only differ slightly, differences shown in red below:
How to Write an Invoice in the UK if You’re VAT Registered
If you’re VAT registered, you must issue and keep copies of all VAT invoices - even ones that are cancelled or issued in error.
There are three types of VAT invoices:
Full VAT invoice - used for most supplies
Simplified VAT invoice - for retail sales under £250
Modified VAT invoice - for retail sales over £250
VAT invoices are usually issued within 30 days of supplying goods or services.
If all goods are exempt or zero-rated, a VAT invoice isn’t required.
Invoicing International Customers
If you invoice in a foreign currency or language and the supply is made in the UK, you must still show the VAT payable in sterling.
You should also keep an English translation available in case HMRC asks to see it.
Common Invoice Payment Terms (Explained Simply)
Your payment terms should be agreed upfront and clearly shown on the invoice. For a bigger deep dive please read our blog post here.
For most small businesses, simple is best:
Payment due within 30 days
Other common invoice terms include:
Payment in advance (PIA) – useful for new customers
Net 10 / Net 30 – payment due within X days
End of month (EOM) – e.g. Net EOM 30
Month following invoice (MFI) – e.g. 15 MFI
Early payment discounts – e.g. 1% 10 Net 30
Stage payments – ideal for large or long-term projects
Common Invoice Payment Methods
Bank transfer (BACS / Faster Payments)
Still the most popular option in the UK. Faster Payments usually clear the same day.
Include:
Bank name
Sort code
Account number
IBAN / BIC / SWIFT
Needed for international payments.
Card payments
Require a merchant account and can be costly unless you process high volumes.
PayPal
Convenient for customers but fees apply.
Cash
Generally not suitable for B2B invoices and carries security risks.
Sending Your Invoice (Timing Matters)
The best time to send an invoice? As soon as you can.
The longer you wait, the longer it takes to get paid.
Goods: invoice before dispatch, on delivery, or Net 30
Services: ask when payment runs happen
Long-term projects: agree staged or monthly invoices
Always double-check invoices before sending.
How to Send Your Invoice
Ask who in accounts actually processes payments
Email is standard - CC your main contact
Send invoices as PDFs (not Word or Excel)
Email subject line tip
Keep it clear:
[Your business name] – Invoice – January 2026
How to Write an Invoice Email
Keep it short and clear:
"Dear [Company Name], Please find attached my invoice dated 5 February 2026 for £1,800.00 in respect of our services. PO number: [if applicable] If you have any questions, please let me know. Kind regards, Jane Smith"
How to Get Paid on Time (Without the Stress)
Have clear T&Cs and get agreement in writing
Agree payment terms upfront
Ask for a PO number
Request PIA from new customers
Use staged payments for large projects
Make payment easy (BACS works best)
Know who controls payments
Chase overdue invoices promptly
Chasing late payments isn’t awkward - it’s professional.
Using accounting or invoicing software can help automate invoices, reminders and payments.
Either way, good invoicing leaves you with more time to focus on what really matters: running your business.
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