The short version
Chase in stages, counted from the due date rather than the invoice date. A reminder in the first week, a statement in the first month, a phone call after thirty days, and a decision about supply after sixty. If this keeps happening across more than one client, the DSO calculator turns it from a feeling into a number you can track month to month.
Work out how late it actually is
Before anything else, count from the due date. An invoice raised six weeks ago on net 30 terms is twelve days past due, and chasing it as though it were six weeks late is how you sound unreasonable to somebody who has done nothing wrong.
The days past due calculator does this and names the aging bucket, which is useful because what you should do changes at each boundary rather than gradually. If the due date on the original invoice was ever vague, fix that going forward with the invoice due date calculator, since a real date is what makes every stage below possible to time.
Week one: a reminder, not a complaint
Short, factual, and quoting the invoice number, the amount and the due date. Most invoices at this stage are not being withheld; they are sitting in an inbox behind a hundred others, or they went to the person who booked the work rather than to accounts.
Ask one question that is easy to answer: is there anything you need from me to get this processed. A missing purchase order reference is a common reason an invoice sits untouched in a company of any size, and it is a two-minute fix once you know.
Subject: Invoice 2214, $860, due 3 days ago
Hi Priya, just flagging that invoice 2214 for $860 was due on Tuesday and I haven't seen it come through yet. I've attached it again along with a payment link so you can settle it in a couple of taps. Let me know if you're waiting on anything from me, like a PO number. Thanks, Marcus.
A payment link on that first email matters more than it looks: half the reason a paid-on-time invoice goes late is that paying it takes more steps than reading it does.
Weeks two to four: send a statement instead
Chasing the same invoice a second time invites a conversation about that invoice: whether it arrived, whether it was right, whether somebody approved it. A statement changes the subject to the balance, and a balance is much harder to have an opinion about.
It also catches the case where they genuinely have lost it. If an invoice is on your statement and not on their ledger, that is found in a minute rather than after a month of chasing something they were never holding.
Send it to the accounts address, not to the person who booked the job. The account statement maker lists every open invoice with its due date and days overdue.
After thirty days: pick up the phone
Email has stopped working by this point, and sending a third one mostly signals that nothing will happen if they keep ignoring you.
Ask for a payment date rather than for payment. A date is something a person can give you, it commits them to something specific, and it gives you a reason to call again that is not a complaint.
After sixty days: decide about supply
This is the point where the question stops being when you will be paid and starts being whether to keep working. Continuing to supply an account that has stopped paying is how a manageable debt becomes an unmanageable one.
The older a debt gets, the less likely it is to be paid in full, and past ninety days the decision is about what the debt is worth rather than when it arrives. The bad debt calculator will show you what writing it off actually costs, which is usually several times the amount itself once you account for the sales needed to replace the lost profit.
Late fees, used carefully
A late fee you never mentioned before the invoice went out is a fee you will probably not collect and may resent having asked for. A late fee stated in your terms and applied consistently is a normal commercial term that most clients accept, and this is the stage to actually charge it: once a client has had a reminder and a statement and still hasn't paid, a fee is no longer a surprise.
Subject: Overdue notice, invoice 2214
Invoice 2214 for $860 was due 28 August and remains unpaid. As stated on the invoice, a late fee of 1.5% per month applies to overdue balances, so the amount now due is $872.90. Please pay by 25 September using the link below. If it's not settled by then I'll need to pause further work until the account is current.
What you can charge is limited by law in many places. The late fee calculator gives you the amount and the wording for both the invoice clause and the reminder.
Questions people ask
When does an invoice become overdue?
The day after its due date. That is why the due date should be an actual date: an invoice marked due on receipt has no clear day it became late, and chasing it starts with an argument about when it arrived.
What should an overdue invoice reminder say?
The invoice number, the amount, the original due date and how many days it is past due, with the invoice attached again and a way to pay. Keep it short and ask whether anything is missing, such as a purchase order number.
When should I start chasing an invoice?
The day after it is due, counted from the due date rather than the invoice date. A short reminder at that point is normal and is not an accusation.
Is it better to email or call?
Email for the first week or two, because it is easy to answer and leaves a record. After about thirty days email has usually stopped working and a call is the next step.
What should I send after the first reminder?
A statement rather than another reminder about the same invoice. It moves the conversation from one invoice they might dispute to a balance they have to account for, and it catches invoices they never received.
Should I charge a late fee or interest?
Only if it was in your terms before the invoice went out, and only if you are willing to apply it consistently. The same goes for interest on an overdue invoice: state the rate on the invoice first. What you can charge is limited by law in many places.
When should I stop supplying?
Pick a point to stop supplying and hold to it. Sixty days past due is a reasonable line, because continuing to supply an account that has stopped paying turns a manageable debt into an unmanageable one.
What does writing off an invoice really cost?
More than the invoice. A write-off costs profit, not revenue, so at a 20% margin $4,200 written off needs $21,000 of new work to replace.
What this is. A guide and template written by Emily Johnson. It is not legal advice. Deposit, cancellation and late fee rules differ by state, so have any wording you rely on checked for your state before it goes on a real document.
Last reviewed by InvoiceTools, Houston, Texas, on 18 September 2026.