Guide
Disclosure: I sell the Freelance Client & Invoice Tracker ($19) linked on this page. The steps below work just as well if you build your own.
An invoice is overdue the day after its due date passes unpaid. The hard part isn't the definition. It's noticing on that day, not three weeks later when rent is due. Below is a small sheet setup that does the noticing for you, and a follow-up schedule to go with it.
Want the ready-made version? The $19 tracker is here.
Step 1: Get the due date right
The due date comes from your payment terms, counted from the invoice date:
- Net 14: issued 1 Oct → due 15 Oct → overdue from 16 Oct.
- Net 30: issued 1 Oct → due 31 Oct → overdue from 1 Nov.
- Due on receipt: due the day they get it. Give yourself a practical window (I use 7 days) before chasing.
If your invoice didn't state terms, the client's accounts team will usually apply their own (often 30 days or more). Put the terms on every invoice from now on.
Formula (issue date in C, terms in days in D):
Due date: =C2+D2
Step 2: Flag it automatically
Add these columns (due date in E, amount in F, paid date in G):
Status: =IF(G2<>"","Paid",IF(TODAY()>E2,"Overdue","Unpaid"))
Days overdue: =IF(G2<>"","",MAX(0,TODAY()-E2))
Conditional formatting: red when Days overdue > 0, amber when the due date is within the next 3 days.
Step 3: Add a "next follow-up" column
Most invoice templates leave this out. Add Last chased (H, a date you type) and Next follow-up (I):
=IF(G2<>"","",IF(H2="",E2+1,H2+7))
That means: first chase the day after the due date, then every 7 days after your last chase. Sort by Next follow-up each morning or week, and whatever is dated today or earlier gets an email.
| Invoice # | Client | Due | Amount | Paid | Status | Days overdue | Last chased | Next follow-up |
|---|---|---|---|---|---|---|---|---|
| 1042 | Pine Studio | 2026-10-31 | $1,200 | Unpaid | 0 | 2026-11-01 | ||
| 1039 | Oak & Co | 2026-09-30 | $450 | Overdue | 13 | 2026-10-08 | 2026-10-15 | |
| 1037 | Harbor Bakery | 2026-09-20 | $300 | 2026-09-22 | Paid |
Step 4: The follow-up schedule
| When | What | Tone |
|---|---|---|
| 3 days before due | Optional heads-up with the invoice attached | Friendly |
| Day 1 overdue | Confirm they received it; ask when it will be paid | Assume it slipped |
| Day 7 | Ask for a specific payment date; copy their accounts address if you have it | Polite, specific |
| Day 14 | Phone or video call. Check your agreement about pausing new work | Direct |
| Day 30 | Written notice: amount, days overdue, any late fee your contract allows, a deadline | Formal |
Day 1 email
Subject: Invoice 1039, due 30 Sep
Hi Sam, a quick check that invoice 1039 ($450, due 30 Sep) reached you. It's attached again. Could you let me know when it's scheduled for payment? Thanks, Alex
Day 7 email
Subject: Re: Invoice 1039, due 30 Sep
Hi Sam, following up on invoice 1039, now 7 days past due. Could you confirm a payment date? If anything is missing on my side, like a PO number or a tax form, tell me and I'll send it today.
Keep every reminder in the same email thread, and log each one in "Last chased".
Notes
- A "we're processing it" reply isn't a date. Ask for the date.
- Late fees only apply if your contract or invoice terms say so. Check before you mention one.
- A free sheet is enough if you can commit to looking at it once a week. If you won't, a free invoicing app that sends reminders automatically is the better choice. Pick the one you'll actually keep up.
A ready-made version
My Freelance Client & Invoice Tracker ($19, Google Sheets or Excel) fills in due dates and Unpaid / Overdue / Paid status on its own, and shows money still owed on a dashboard. Note that it doesn't send reminders. You still send the emails above yourself.