When an invoice goes past due

The invoice went out August 3 on Net 15, so it was due Tuesday the 18th. It is now the following Monday, the $4,200 is not in the account, the customer was friendly all job, and you have drafted the same email three times without sending it.

That hesitation is the expensive part. A past-due invoice may be an unopened email, a missed check run, or a refusal, and you cannot tell which until you ask. Run the same sequence every time.

First, rule out the boring reasons

Before you chase anybody, rule out a mechanical explanation.

• Did it reach someone who can pay it? On residential work, the person whose name is on the account, not whoever was home. On commercial work, accounts payable, not the site superintendent, who cannot release a check.
• Is something missing that their system requires? Commercial payers routinely hold an invoice with no purchase order number, no cost code, or no signed lien waiver for the pay period. Nobody calls to tell you.
• Does the due date appear as a date? "Net 15" means nothing to a homeowner; "Due August 18, 2026" does. Click your own pay link while you are in there.
• Does the amount match what they approved? An invoice higher than the estimate with no signed change order behind it is not a late payment. It is a dispute the customer has not started yet.

Fix what you find, resend, and start the clock from the resend date.

The sequence: day 3, day 10, day 14, day 21

Those intervals are a default. Move them in when the balance is a large share of your month, or the customer is new. Move them out for a commercial account on a monthly check run, where day 3 is pointless and the real question is which run you are in. Never move day 21: a deadline you slide teaches the customer that your deadlines slide.

One thing not to add is a late fee your signed estimate or contract never mentioned; charging one after the fact gives the customer something to argue about instead of paying. That clause is its own decision, made before the job.

Write for the person who forgot, until you know they didn't

The first message assumes an oversight, because that is usually what it is. No "as per my previous email," no threat, no wounded tone.

Subject: Invoice 1042 — quick check

Hi Dana,

Invoice 1042 for $4,200 was due Tuesday, August 18, and I don't see it in yet. Attached again in case it went to spam.

If something doesn't look right, tell me and I'll sort it out. Otherwise, what day will it go out?

Thanks, Mike

The day-21 notice is a different document: dated, restating the facts, naming a deadline, and saying what follows it without drama.

Subject: Past due notice — Invoice 1042, $4,200

Dana,

Invoice 1042, dated August 3, 2026, for $4,200, was due August 18, 2026. It is now 21 days past due, with no payment and no payment date.

Payment in full is due by September 15, 2026, by check to the address below or by card at the link on the invoice.

If I have no payment or signed payment plan by that date, I will refer this balance for collection.

Mike Reyes, Reyes Tile & Stone

The call gets a date; the email records it

Day 14 is a phone call because email lets the customer keep not deciding. Open with the fact, then stop talking. "Hi Dana, it's Mike — I'm calling about invoice 1042, the $4,200 from the bathroom. It was due the 18th and I wanted to check where it stands." Let the silence work.

You are on the call for two things: what date and by what method. "Soon" and "when the deposit clears" are not dates. Ask again: "What date should I expect it, and is that a check or a card?" Then repeat the answer back.

If a complaint surfaces, do not renegotiate the price on the spot. Ask for the issue in writing, name a day you will look at it, say plainly that the undisputed portion is still due. Then email the same day: "Confirming our call — you'll mail a check on September 5, and I'll look at the grout line Thursday."

The answer you get tells you which problem you have

"I never got it." Low risk if the address checks out. Resend, confirm receipt in writing, restart the clock. Twice, and either the address is wrong or the story is.

"We pay on the 30th." Common on commercial and property-management work. Get the invoice cutoff and the check-run date, calendar both, follow up the day after the run. Then price that delay into your next payment terms with them.

"There's a problem with the work." Pause the sequence and handle the complaint separately. Fix what is genuinely yours, document it, get written confirmation it is resolved. Collecting from a customer with an unanswered legitimate complaint goes badly; a documented fix removes their last reason to sit still.

"Money is tight." Often solvable. A written installment plan with dates and amounts collects more than a standoff — see partial payments and payment plans. Get it signed, and treat a missed installment as a return to day 21.

Silence. The worst answer, and the one people wait longest on. A customer who replied twice and then went quiet has decided something. Believe it.

When patience stops being the right move

Any one of these ends the reminder phase:

• 30 days past due with no payment date on record
• Two promised dates missed
• Someone who was responsive stops replying
• A bounced check, or a card payment they reverse
• You hear other trades on the same job are also unpaid

Deadlines are also running that reminders do not pause. On construction work, your state's mechanic's lien rules set the windows for a preliminary notice and for the lien filing itself, usually counted from your last day of work or last delivery of materials. Some are a matter of weeks, and missing one gives up your leverage permanently. Look up the statute for the state the property sits in, or ask a construction attorney there. The deadline for suing on the debt is separate, longer, and also state law.

What comes next — a demand letter, a collection agency, small claims, or the lien itself — is covered separately, and each works better with the file you just built.

The record that makes the notice easy to write

The day-21 notice only lands if you can state the approved amount and the date it was approved without reconstructing it from memory. That part of the record starts in DoneQuote: the estimate the customer approved, the timestamp on that approval, and any change order written into a later version stay with the job instead of scattered through your sent folder. The figures you quote are then the figures the customer agreed to.