# Late-payment interest calculator (UK)

Work out the statutory interest and fixed compensation you can claim on an overdue commercial invoice under the Late Payment of Commercial Debts (Interest) Act 1998. Runs entirely in your browser.

From Creditcorp — educational information, not legal advice.

## Inputs

- **Invoice amount** — the outstanding principal (£).
- **Days overdue** — number of days past the agreed payment date (or 30 days if none was agreed).
- **Bank of England base rate** — the current base rate (%). The Act adds 8% to this.

## How the calculation works

Under the Late Payment of Commercial Debts (Interest) Act 1998:

- **Statutory interest rate** = Bank of England base rate + 8% per annum.
- **Daily interest** = invoice amount × (annual_rate / 365) × days_overdue.
- **Fixed compensation** — a flat sum based on the invoice value:
  - Up to £999.99 → £40
  - £1,000 to £9,999.99 → £70
  - £10,000 and over → £100

Formula:

```
annual_rate  = base_rate + 0.08
daily_rate   = annual_rate / 365
interest     = invoice × daily_rate × days_overdue
compensation = £40 | £70 | £100  // based on invoice size
total_claim  = interest + compensation
```

## Who can use this?

Any business selling to another business on commercial credit terms. The Act applies to UK B2B transactions. It does not apply to consumer sales or public authority contracts under separate rules.

## Links

- [What a business loan agreement covers](/learn/what-a-business-loan-agreement-covers/)
- [The cash-flow gap explained](/learn/cashflow-gap-explained/)
- [Apply at credicorp.co.uk](https://credicorp.co.uk/apply/)