Work out what a late-paying client actually owes you, interest, fees, the lot.

Sound familiar?

• “Invoice was due 30 days ago. They've gone quiet and I don't know what I can legally charge.”
• “They're saying their 'standard terms' are 90 days. Can they just decide that?”
• “The job was finished in January, I'm still chasing in April.”
• “I've heard I can charge interest but I've no idea what rate or how.”

What this tool does

Calculates statutory interest (currently base rate + 8%), the fixed compensation fee, and any recovery costs for each overdue invoice. It applies the Late Payment of Commercial Debts (Interest) Act 1998 to the dates and amount you give it.

What the law actually says

• •The Late Payment of Commercial Debts (Interest) Act 1998 applies to B2B invoices, which includes most sub-contract construction work. It gives you interest and a fixed compensation fee automatically, whether the contract mentions it or not.
• •Contracts cannot water down your statutory right below a 'substantial remedy'. Clients trying to impose 90 or 120-day terms often fall foul of this.
• •You can add these charges retroactively. You don't need to have warned the client in advance.

What to do next

• If they still won't pay: Small Claims Check
• Send a chaser that works: Late payment demand letter with statutory interest
• To understand retention: Retention Calculator