1. Eligibility
ChaseKit treats statutory interest and fixed compensation as potentially available when goods or services were supplied to another business or a public authority and payment is late. Consumer debts are excluded. A contract can also provide its own substantial remedy, so the statutory calculation is not automatically the right one for every invoice.
2. Interest formula
Daily interest = unpaid amount × annual rate ÷ 365.
Interest accrued = daily interest × overdue days.
The statutory annual rate is eight percentage points above the relevant Bank of England reference rate. ChaseKit keeps the base-rate field editable because the rate relevant to a debt may depend on when it became late. Confirm the applicable reference rate before sending a claim.
3. Fixed compensation
- Debt below £1,000: £40
- Debt from £1,000 to £9,999.99: £70
- Debt of £10,000 or more: £100
The calculator applies one fixed sum to the unpaid invoice when the debt is eligible and overdue. It does not decide whether multiple invoices should be treated separately.
4. Dates and rounding
Overdue days run from the payment due date to the calculation date, using calendar days. Calculations retain full precision internally and display money to two decimal places. Partial-payment schedules are not split into separate interest periods; enter the remaining unpaid balance and review the result manually.
5. Source review
The default Bank Rate is 3.75%, verified against the Bank of England decision published on 30 July 2026. The figure is reviewed after scheduled Monetary Policy Committee decisions. ChaseKit displays the last verification date on the calculator so a user can see whether the default needs checking.
6. What ChaseKit does not decide
ChaseKit cannot determine whether a contract contains a substantial alternative remedy, whether a debt is disputed, which jurisdiction applies, whether a public-body rule changes the due date, or whether commencing formal proceedings is appropriate. It is an administrative drafting aid, not legal advice.