Invoice Generator

Free Invoice Templates for UK Freelancers & Small Businesses

Whether you're a freelancer, sole trader, contractor or small business owner, a professional invoice is essential for getting paid. KwikSum's free online invoice maker lets you create, customise and download a PDF invoice in minutes — no account required, no software to install, and no cost.

What Must a UK Invoice Include?

Under HMRC rules, every invoice issued by a UK business must contain: your business name and address, the client's name and address, a unique sequential invoice number, the date the invoice was issued, a clear description of the goods or services supplied, and the total amount owed. For VAT invoices, you must also show your VAT registration number, the VAT rate applied to each item, and the total VAT charged. If you supply at multiple VAT rates, each must be shown separately. This free invoice generator covers every required field.

Invoice Numbering for Sole Traders & Limited Companies

Invoice numbers must be unique and sequential — no gaps, no duplicates. Common formats include INV-001, 2026-001, or a simple running number starting at 001. KwikSum's generator auto-increments the invoice number each time you download, so your records stay in order. HMRC may query missing numbers during a tax investigation or VAT audit, so it's important to never reuse or skip numbers.

Payment Terms & Getting Paid Faster

The UK standard is 30 days ("net 30"), though many freelancers opt for 14 days to improve cash flow. Always include your payment details on the invoice — BACS sort code and account number, or a payment link. Studies show invoices with clear payment instructions are paid up to 3 days faster. Use the Payment Details field to add your bank details and reference instructions.

VAT Threshold & When to Charge VAT

You only need to add VAT to invoices if you're registered for VAT. The UK VAT registration threshold is £90,000 in taxable turnover over any rolling 12-month period (2024/25). Below that threshold, set all line items to N/A — the invoice total will show as a simple amount with no VAT breakdown. Once registered, use 20% for most goods and services, 5% for qualifying reduced-rate items (such as domestic energy), and 0% for zero-rated supplies.

Self-Employed & Sole Trader Invoice Tips

As a sole trader, you invoice under your own name (or a trading name). You don't need a company number — just your name, address and contact details. If you trade under a business name that isn't your own name, you must still include your personal name somewhere on the invoice. Keep a copy of every invoice you send for at least five years for Self Assessment purposes.

Related Tools

Use the VAT calculator to verify VAT amounts before invoicing, the salary calculator to understand your take-home as a sole trader, or the hours calculator to tot up billable time before you invoice.