The due date has come and gone, and the money hasn't arrived. Often the invoice is just sitting in someone's inbox, so a clear, friendly reminder is the right first move. This guide covers when to follow up, what to include, three emails you can copy, and how to resend the invoice and track payments with Invoice Cat, our invoice app for iPhone.
When to follow up
A simple schedule keeps you from chasing too early or leaving it for months:
- A few days before the due date (optional): a short heads-up, useful for a new client or a large amount.
- A day or two after the due date: the first reminder.
- About a week later: the second reminder. Ask if anything is holding it up.
- Two weeks or more after the due date: a final reminder, then a phone call.
Space them to suit your client and your payment terms. In Invoice Cat, an invoice counts as overdue from the day after its due date.
What every reminder should include
- The invoice number, so their accounts team can find it.
- The amount still owed. If they paid part of it, say what's left, not the original total.
- The original due date.
- How to pay you: bank details, PayPal or whatever you accept.
- The invoice itself, attached again, so nobody has to dig for it.
Put the invoice number in the subject line too. Keep the tone neutral: you're pointing out a missed date, not accusing anyone.
Reminder email templates
Replace the parts in square brackets.
First reminder (a day or two after the due date)
Subject: Invoice [number]: friendly reminder
Hi [name],
Just a quick reminder that invoice [number] for [amount] was due on [date]. I've attached it again in case it got lost. Payment details are on the invoice.
Let me know if you need anything from me to process it.
Thanks,
[your name]
Second reminder (about a week later)
Subject: Invoice [number]: now [N] days overdue
Hi [name],
I'm following up on invoice [number] for [amount], which was due on [date] and is now [N] days overdue. The invoice is attached again.
Could you let me know when I can expect payment, or whether anything is holding it up, such as a missing purchase order number?
Thanks,
[your name]
Final reminder (two weeks or more after the due date)
Subject: Final reminder: invoice [number]
Hi [name],
Invoice [number] for [amount] was due on [date] and is still unpaid, and I haven't heard back about my earlier reminders. Please arrange payment by [date], or call me on [phone number] so we can sort it out. The invoice is attached again with the payment details.
Thanks,
[your name]
Only say what you'll actually do. Thinking about late fees, interest or a collection agency? Check what your contract and local rules allow before you mention any of them.
Resend the invoice with Invoice Cat
Invoice Cat doesn't send reminders for you: no automatic emails, no reminder alerts, and nothing is sent by itself. You write the reminder; the app gets the invoice ready to go with it.
- Open the invoice. The strip at the top says where it stands, such as 12 days overdue.
- Tap Preview & send. The PDF still shows the Due date, the Balance due and your Payment details (if you added them).
- Tap Email (shown when Mail is set up on your iPhone). Mail opens with the PDF attached, the client's email filled in if you added one, and a subject like "Invoice INV-0042 from [your name]". The message that's filled in reads like a first send ("Attached is invoice … due …"), so swap it for your reminder text. Or tap Send to share the PDF through another app.
Don't change the due date or terms before you resend; the reminder is about the original date. And resend the same invoice rather than using Duplicate, which makes a new invoice with a new number and today's date.
Keep track of what's paid
- Home shows Outstanding, Overdue (the amount and how many invoices) and what was paid this month (for example Paid in October). Below that, an Overdue list shows up to five, earliest due date first.
- In the Invoices tab, filter by Unpaid (which includes overdue ones), Overdue or Paid, or search by number, client or item.
- The Clients tab shows what each client Owes.
When the money arrives, tap Mark as paid on the preview or in the ⋯ menu on the invoice. From the Invoices list, swipe right and tap Paid, or touch and hold and tap Mark as paid. If it came in on an earlier day, open More options and change Paid on under Payment. The PDF then shows PAID and the date. Marked the wrong one? Mark as unpaid puts it back.
Paid in part? Under More options, type the amount in Deposit received. The PDF shows Paid to date and the Balance due, and the email message names what's still owed.
Several unpaid invoices for one client? With Invoice Cat Pro, Statement on the client's page makes one PDF of their invoices, what they've paid and what they still owe, including how much of it is overdue.
To head off late payments next time, agree payment terms before you start and put them on every invoice; see how to invoice a client as a freelancer.
What it costs
Invoices, estimates and clients are free and unlimited, and so are preview, send, email and print. There's no watermark, no ads, no account and no subscription. Invoice Cat Pro is an optional one-time purchase that adds Saved items, Repeat monthly and Statements. More on the Invoice Cat page.
Quick answers
How long should I wait before following up on an unpaid invoice?
The first reminder a day or two after the due date, a second about a week later, a final one after two weeks or more.
How do I politely ask a client to pay an overdue invoice?
Keep it short and neutral: invoice number, amount still owed, original due date, how to pay, and the invoice attached.
Can I charge a late fee on an unpaid invoice?
Check what your contract and local rules allow. Invoice Cat doesn't add late fees or interest.
Does Invoice Cat send payment reminders automatically?
No. You write the reminder yourself; Invoice Cat attaches the PDF and shows which invoices are overdue.
Try Invoice Cat
Try Invoice Cat: free, no watermark, no sign-up → iyio.com/apps/invoice-cat