How to follow up on unpaid invoices
Follow up the day after an invoice becomes overdue, not a week later, and keep the first message short and factual. Escalate on a predictable schedule — a reminder at day 1, a firmer note at day 7, a call at day 14, and a formal demand at day 30 — and always send to accounts payable as well as your contact.
Before it is late
A short note a few days before the due date prevents more late payments than any amount of chasing afterwards. It is not a chase — it is a reminder that the invoice exists and that nothing is blocking it, which is exactly when a missing PO number or a wrong email address surfaces.
A follow-up timeline that works
| When | Action | Tone |
|---|---|---|
| 3 days before due | Friendly reminder, re-attach the invoice | Neutral, helpful |
| Day 1 overdue | Short note: invoice is now overdue, re-attached | Factual |
| Day 7 | Ask directly when payment will be made | Firm, still warm |
| Day 14 | Phone call, then confirm in writing | Direct |
| Day 30 | Formal demand, reference terms and any late fee | Formal |
What to say
Keep it under five sentences. State the invoice number, the amount, the due date, and ask a specific question — “Can you confirm the payment date?” is harder to ignore than “Just checking in”. Always re-attach the invoice: the single most common reason for non-payment is that nobody can find it.
When it keeps happening
- Shorten the terms for that client on the next engagement.
- Ask for a deposit before starting work.
- Invoice in stages rather than on completion, so exposure never accumulates.
- Confirm the AP contact and PO process before you start, not after the invoice is late.