Free invoicing and late payment tools for UK businesses
Six free tools built on UK rules: the Late Payment Act 1998, the Pre-Action Protocol for Debt Claims, HMRC's VAT number check and the e-invoicing plans for April 2029. No sign-up; most calculations run in your browser.
- Late payment and credit control
Late payment interest calculator
Calculate statutory interest at Bank Rate + 8% (11.75% in 2026) and the £40, £70 or £100 fixed sum on a late business invoice, under the Late Payment Act 1998.
- Late payment and credit control
Payment terms calculator
Find the date a UK business invoice becomes late: 30 days by default under the Late Payment Act, and the usual 60-day limit for agreed terms. Free, no sign-up.
- VAT and invoice details
VAT number checker
Check a UK VAT number (GB + 9 or 12 digits) against HMRC and an EU VAT number in VIES, with the registered name and address when available. Free, no sign-up.
- E-invoicing
E-invoicing readiness check
Three questions to see what applies to your business today (Making Tax Digital) and what was announced for April 2029, with the legal status of each step.
- E-invoicing
E-invoice validator
Upload a UBL or CII e-invoice: the validator applies the EN 16931 and Peppol BIS Billing 3.0 rules and explains every error in plain English. Free, no sign-up.
- Late payment and credit control
Letter before action generator
Write a payment reminder, a final reminder or a letter before action (or a Letter of Claim) for an unpaid UK invoice, with statutory interest if you claim it.
Why these tools
UK rules, not a translation: statutory interest at Bank Rate + 8%, fixed sums of £40, £70 or £100, and the pre-action letters used in England and Wales.
Clear about the law: what is in force is shown as such; announcements and bills (April 2029 e-invoicing, Commercial Payments Bill) are never presented as law.
Every page lists its official sources (legislation.gov.uk, GOV.UK, HMRC, Bank of England, Ministry of Justice) and the date the rules were checked.
Read our guide: UK e-invoicing, from the 2025 consultation to April 2029
Frequently asked questions
Are these tools really free?
Yes. No account and no card needed. You can get a result by email if you want to keep it; that is optional.
Which parts of the UK do they cover?
The Late Payment Act 1998 applies across the UK. The pre-action letters follow the rules of England and Wales; Scotland and Northern Ireland have their own court procedures, which these tools do not cover.
Do the tools apply the Commercial Payments Bill?
No. The Bill is still going through Parliament and is not law. The tools apply the law in force today and will be updated if the Bill is passed and comes into force.
Is the result legal advice?
No. The tools apply the published rules to the figures you enter. For a disputed or large debt, take advice from a solicitor or an adviser.