Dear [Client name],
Invoice [Invoice number] for [Amount], due on [Due date], is now 60 days overdue. I have written on [dates of previous reminders] and have not received payment or a response.
The amount now owed, including statutory interest and compensation under the Late Payment of Commercial Debts (Interest) Act 1998, is [Total owed].
Please pay this amount, or contact me to agree a payment plan, within 7 days. If I don't hear from you, I will send a formal letter before action, which is the step before a court claim.
Yours sincerely,
[Your name]