How long should I wait to chase an unpaid invoice — and what do I say?

Nobody gets into plumbing, HVAC, or electrical work because they enjoy chasing money. But if you did the job and sent the invoice, the money is yours to collect — and asking for it is not rude.

The tradespeople who get paid fastest usually aren't tougher than everyone else. They just have a routine: chase on a schedule, say the same clear things every time, and don't let an unpaid invoice sit for a month. Here is that routine.

First, check the invoice before you chase it

Before you send anything, check three things:

• Is it right? Right customer, right job, right amount, right due date. A wrong total gives the customer a reason to wait while you fix it.
• Did they actually get it? Check the email or phone number you sent it to. Plenty of "unpaid" invoices went to an old email or a partner who never passed it on.
• Has anything already been paid? Check for a partial payment or a deposit. Chasing a customer who already paid damages a good relationship fast.

If the invoice is wrong, fix it and resend it with a short note — "Corrected invoice attached, total now $X, due [date]" — and don't chase the old version.

The timeline that works for most solo tradespeople

Guides differ by a day here or there, but they agree on the shape: a friendly nudge early, a firmer follow-up, a phone call, then a final notice. Use this as your default, and adjust only when the customer gives you a real reason to — like a promised payment date.

A few days before the due date (optional). A short heads-up — "Invoice #104 for $850 is due Friday" — catches invoices that would otherwise slip through a busy week.

1–3 days past due: the friendly reminder. This is the most important step, and the one most people skip. Send a short message, by text or email, and assume the customer simply forgot. Restate the invoice number, the amount, and the due date, reattach the invoice, and make it easy to pay.

About 7 days past due: the direct follow-up. If the first reminder got no reply, send a second message that is still polite but asks for something specific: a payment date. "Could you let me know when this will be paid?" is stronger than "just checking in," because it asks for an answer.

About 14 days past due: pick up the phone. A call is harder to ignore than another email, and it usually tells you what is really going on: they forgot, they never saw the invoice, they have a question about the work, or money is tight. Each needs a different response. Whatever they promise, confirm it in writing right after: "As discussed, payment by Friday, November 13."

About 30 days past due: the firm final notice. Now the tone changes. State plainly that the invoice is 30 days overdue, list the reminders already sent, set a final deadline — usually 7 days — and say what happens next if it is not paid or no payment plan is agreed. Only mention consequences you actually intend to follow through on, like pausing further work or passing the account to collections.

About 60 days past due: decide, don't just send another reminder. Another copy-paste nudge rarely changes anything now. Choose between a formal demand letter, a collection agency, or small claims court — or, sometimes, a payment plan. The decision matters more than another email.

What to say at each step

Keep every message to a few lines. Long, emotional emails get skimmed or ignored; short, factual ones get paid:

Friendly reminder (1–3 days past due):

Hi [Name], just a quick reminder that invoice #[number] for $[amount] was due on [date]. I've attached it again here. Let me know if you have any questions — happy to get this sorted.

Direct follow-up (about 7 days past due):

Hi [Name], following up on invoice #[number] for $[amount], due [date] — we haven't received payment yet. Could you let me know when we can expect it? If there's an issue with the invoice, I'm happy to talk it through.

Firm final notice (about 30 days past due):

Hi [Name], invoice #[number] for $[amount], due [date], is now 30 days overdue. I've followed up on [dates of earlier reminders] and haven't received payment or a reply. Please arrange payment by [date, 7 days out], or contact me to agree a payment plan. If I don't hear from you by then, I'll need to consider next steps to recover the amount.

Notice what none of these do: apologize for asking, guilt-trip the customer, or threaten legal action in the first message.

If the customer disputes the work or can't pay right now

A dispute and a cash-flow problem are not the same thing, and mixing them up costs you money.

If they dispute something: stop the reminder sequence and deal with the dispute itself. Ask exactly what they are unhappy with, in writing. If there is a real issue, it is usually cheaper to fix it than to fight over it. If the work is fine and the invoice matches the quote, say so calmly and point to the quote, the photos, and the signed agreement.

If they can't pay in full right now: a payment plan beats a standoff. Get it in writing — amount, dates, and what happens if a payment is missed — and make the first payment soon, not "next month." Splitting a $1,200 invoice into two or three dated payments often gets you paid faster than more reminders.

If they go quiet completely: keep everything in writing from here on. Save every message, call note, and version of the invoice. That paper trail is what makes any later step — a demand letter, collections, or court — actually work.

When to escalate beyond reminders

This is general information, not legal advice — rules vary by state, and for a large or complicated debt, talk to a local attorney first. For a typical solo trade invoice, the options in order are:

A formal demand letter. A short letter stating the amount owed, the work done, the reminders already sent, and a final deadline (often 10–14 days). Send it in a way you can prove delivery, like certified mail or email with a delivery record.

A collection agency. Agencies usually work on contingency — they take a percentage of whatever they recover, so you receive less than the full invoice. That trade can be worth it for an old, ignored debt you would otherwise write off, but check what the agency charges before you hand over a customer's details.

Small claims court. Small claims courts are designed for exactly this kind of dispute, and you generally do not need a lawyer. Limits vary widely by state — many cap claims somewhere between $5,000 and $10,000, with some lower and some higher — so check your state's limit, and filing fees are usually modest for smaller claims. Bring your quote, the invoice, photos of the work, your demand letter, and your record of every reminder. Know this first, though: winning a judgment does not automatically put money in your account, so weigh the time and cost against the amount owed.

Pausing further work. Don't keep doing new work for a customer with an unpaid balance and no payment plan. Say it calmly and in writing: "I'm happy to book the next job once the outstanding balance is cleared."

How to make the next invoice easier to collect

Chasing gets easier when the invoice itself does less damage. Put payment terms in the quote before work starts, not on the invoice after it. Use a specific calendar due date ("Due November 13") instead of shorthand like "Net 14." For bigger jobs where you buy parts out of pocket, agree a deposit in writing first. And track every invoice as paid or unpaid from the moment you send it — a list you check each week beats a perfect system you never open.

That tracking step is where a lot of solo tradespeople lose the thread, because the invoice leaves the phone and then lives nowhere. If you already run jobs from an app, check whether it keeps the invoice and its paid-or-unpaid status with the job itself. ServiceFlow, for example, sends numbered PDF invoices with paid and unpaid tracking from the same screen you run the job from.

Send the invoice on the day, check the list weekly, and chase on schedule.

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Chasing invoices is easier when nothing slips through the cracks. ServiceFlow is built for solo tradespeople — booking, scheduling, and invoicing from your phone. Join the free closed beta and try it on your next job.