Find the blocker first
When an invoice to another business goes late, the usual reasons are boring: it went to someone who forwarded it to nobody, it’s waiting for a PO number or a W-9, it missed this month’s payment run, or someone in the customer’s team has a question they haven’t asked yet. Outright refusal to pay is rare.
That changes how the first few reminders should read. They’re questions, not demands: is this with the right person, does it need anything from us, when is it scheduled? Pressure comes later, and only if a customer goes quiet.
It’s worth getting right. In a February 2026 Bluevine survey of 1,052 US small-business owners, 28% had more than $5,000 tied up in unpaid invoices, and nearly 3 in 10 had delayed paying themselves because customers paid late.
The cadence, day by day
This is a starting point for net 30 B2B invoices. Shift it for your terms and your customers.
| When | To | The message, in one line | Tone |
|---|---|---|---|
| 3 to 5 days before due | Billing contact | Heads-up that it’s due on the date, with the pay link. | Helpful |
| Day 1 late | Billing contact | It was due yesterday; here’s the link; anything you need from us? | Friendly |
| Day 7 | Billing contact | Can you tell me when it’s scheduled to be paid? | Direct |
| Day 14 | Billing contact, cc accounts payable | Two weeks late; copying AP in case it hasn’t reached them. | Firm |
| Day 21 | Phone | A call to whoever approves payment. | Personal |
| Day 30 | Billing contact and AP | Final reminder: what you need, by when, and what happens next. | Formal |
| Day 45 to 60 | Decision maker | Written demand, or a decision about pausing work. | Formal |
Two rules make any cadence work. Every message includes the invoice number, amount, due date and a way to pay. And every message stops the moment the customer pays, promises a date, or raises a problem. Nothing undermines a collections process faster than a reminder sent the day after someone said “paying Friday”.
Who to write to, and when
The person who received the invoice is often not the person who pays it. Project managers, office managers and founders forward invoices; accounts payable pays them. Widening the circle in steps keeps things polite:
- Start with the billing contact. They know the job and can confirm it’s approved.
- Add accounts payable at about two weeks. Say why, plainly: “copying your AP team in case this hasn’t reached them.” Most people are grateful.
- Go to the decision maker last. The owner or finance lead, by phone if you can, once email has failed.
Keep a note of who actually paid last time. If AP paid within a week of being copied in, copy them at day 1 next time.
Handling the replies
Every reply tells you where the invoice is stuck. Treat them as data, not just as messages to answer.
| They say | It means | Do this |
|---|---|---|
| “We’ll pay Friday.” | A promise to pay | Note the date, stop reminders until then, check on Monday. |
| “We were billed twice.” | A dispute | Stop chasing that invoice, investigate, reply with the facts. |
| “Can you add our PO?” | A question | Fix and resend the same day. This is the fastest money you’ll get. |
| “Paid on the 20th.” | Already paid | Hold reminders, find the payment, apply it. |
| “I don’t handle this anymore.” | Wrong contact | Ask who does, update the contact everywhere. |
| Out-of-office | Not yet read | Wait until they’re back, then resend. |
Disputes deserve special care. Keep chasing the customer’s other, undisputed invoices; a disagreement about one shouldn’t freeze the rest. But stop chasing the disputed one until it’s resolved, or you’ll be arguing about tone instead of the problem.
Fewer invoices to chase
The cheapest invoice to collect is the one that never goes late. Intuit’s Late Payments Report 2026 found that 55% of businesses on net 30 terms had overdue invoices, against 26% of businesses that asked for payment immediately. You can’t put every customer on immediate terms, but you can:
- Take deposits on large jobs before the work starts.
- Put a pay link on every invoice, so paying is one click instead of a bank login.
- Collect the PO number, W-9 and AP contact before the first invoice, not after the first reminder.
- Agree in writing what happens when invoices go unpaid, so day 45 isn’t a surprise for either of you.
How much of this OnDue runs
OnDue is in early access. Against the cadence above, today it:
- Drafts days 1, 7, 14 and 30. Each draft waits for your approval. The heads-up before the due date, other schedules and per-customer cadences are Coming soon
- Doesn’t widen to accounts payable for you. Reminders go to the invoice’s email contact in your books; add AP there, or copy them yourself.
- Sorts the replies the way the section above describes: promises hold the invoice, disputes and questions come to you.
- Doesn’t phone anyone. The call at day 30 is yours.