Free Tools

Free Tools for UK Tradespeople

Instant calculators for UK sole traders and CIS contractors. No signup, no data stored — results appear as you type.

CIS

CIS Tax Calculator

Calculate your CIS deduction instantly — enter gross amount, select 0%, 20% or 30% rate, and see the net payable in seconds.

Instant calculation →
Late Payment

Late Payment Interest Calculator

Calculate statutory interest on overdue invoices under the Late Payment Act 1998. Current rate: Bank of England base rate + 8%.

Instant calculation →

Why Use These Tools?

UK sole traders and CIS subcontractors deal with complex deduction calculations on every invoice. These free tools give you instant, accurate figures so you always know exactly what you're owed — and what you can claim when clients pay late.

All calculations happen directly in your browser. No data is sent to any server, no account required.

More Than Just Calculators

FlashBill does these calculations automatically on every invoice you send. Try it free →