15‑day payment reminder and late‑interest notice

Delete the options that do not apply. Replace every bracketed field. Do not leave in an interest claim unless you have checked that it is permitted and correctly calculated.

Subject: Payment reminder — invoice [invoice number] — [business name]

To: [buyer contact / accounts-payable address]
Date: [date sent]

Hello [contact name],

I am following up on invoice [invoice number] for [currency and amount], issued on [invoice date] for [brief description of goods or services]. The payment due date shown on the invoice / agreed in our terms is [due date]. Our records show that [amount outstanding] remains unpaid as of [date].

If not yet overdue: Please arrange payment by [requested payment date], or let me know if you need a copy of the invoice or supporting documents. Our requested payment period is [15 days / other period], subject to our agreement and applicable local rules.

If overdue and not disputed: Please arrange payment of the outstanding principal, [currency and amount], by [date]. If you have already paid, please send the payment date and reference so I can reconcile it.

Interest, only if applicable: Under [contract term or applicable legal provision], I understand that late interest may be due on the eligible overdue amount. My calculation is: principal [amount]; rate and basis [rate and source]; period [start date to calculation date]; calculation method [method]; interest claimed to [date] [amount]. Interest may continue to accrue only as permitted by the applicable terms and rules. Please tell me promptly if you believe this calculation or entitlement is incorrect. If you have not verified an entitlement, replace this paragraph with: “Please let me know whether you will consider a reasonable late-payment charge. I am checking the applicable terms and local rules before making any formal interest claim.”

If you dispute any part of the invoice: Please identify the specific amount you dispute, the reason, and any supporting information by [date]. Please also confirm whether the remaining, undisputed amount can be paid by [date]. I am available to resolve a genuine query promptly.

Please reply to [email / phone] with either confirmation of payment, a firm payment date, or the details of any dispute. If I do not hear from you or receive payment by [date], I may consider the next appropriate steps available under our agreement and local rules.

Thank you,
[your name or chosen business contact]
[business name]
[contact details]
[optional: invoice attachment / secure payment link]