You finished the job. Fixed the water heater. Customer seemed happy. You sent the invoice. Then nothing. A week passes. Two weeks. You text. No response. You call. Voicemail. The invoice sits in your system with a red "Overdue" flag and you're wondering if you're ever going to see that $1,200. Here's exactly what to do — and what most plumbers do wrong.
The mistake most plumbers make
They wait too long. Then they get aggressive too fast.
Here's the pattern: invoice goes out. Plumber waits 30 days because "I don't want to seem pushy." Day 31 hits and suddenly they're furious. They send a blunt text: "Your invoice is overdue. Payment is required immediately." Customer gets defensive. Relationship sours. Invoice still doesn't get paid.
The right approach is the opposite. Follow up early and often — but keep it friendly until it's clear the customer is actively avoiding you. Most unpaid invoices aren't malicious. They're forgetful. They're cash-strapped this week. They're waiting on their own payment to clear.
Your job in the first two weeks is to remind them gently and make payment as easy as possible. Your job after two weeks is to escalate — but still professionally.
"Most unpaid invoices aren't malicious. They're forgetful. Follow up early — while the job is still fresh — and you'll close most of them without ever raising your voice."
The 30-day collection timeline
- Day0
Invoice sent
Send the invoice immediately after job completion
Don't wait until you get home. Send it from the job site via text or email with a payment link. The faster you invoice, the faster you get paid. "Job complete. Here's your invoice: [link]. Payment clears in 1–2 business days."
- Day3
First reminder
Friendly check-in — assume good intent
"Hey [Name], just following up on the invoice from Tuesday's water heater job. Let me know if you have any questions. Payment link is here: [link]."
- Day7
Second reminder
Still friendly, but more direct
"Hi [Name], wanted to check in on the outstanding invoice for $1,200. Is there anything I can help with to get this wrapped up? Happy to answer any questions."
- Day14
Phone call
Call them directly — not just text
At this point, texts aren't working. Pick up the phone. Keep it conversational: "Hey, I'm calling about the invoice from two weeks ago. Just want to make sure everything's okay on your end. Is there a reason we haven't been able to get this closed out?"
- Day21
Final notice
Escalation warning — still professional
"Hi [Name], this is my final reminder before I need to escalate this unpaid invoice. If I don't hear from you by [specific date], I'll have no choice but to move forward with collections. I'd prefer to avoid that. Please reach out."
- Day30
Escalation
Collections agency or small claims court
If they still haven't responded, you're now dealing with someone who is either financially unable to pay or actively avoiding payment. At this point, you decide: write it off, send it to collections, or file in small claims court.
Why customers don't pay (and how to handle each scenario)
Not all non-payment is the same. Here are the four most common reasons — and what actually works for each one.
They forgot
The customer meant to pay. They got busy. The email got buried. Life happened.
What works
A simple text reminder with the payment link. "Hey, just a quick reminder about the invoice from last week. Here's the link if you still need it: [link]." Most get paid within 24 hours of the reminder.
They're waiting on money
Customer wants to pay but doesn't have the cash right now. Maybe waiting on their own paycheck. Maybe an unexpected expense. They're embarrassed to admit it.
What works
Offer a payment plan. "If cash flow is tight this week, happy to split this into two payments — $600 now and $600 next Friday." A slow payment beats no payment.
They're unhappy with the work
They haven't said anything, but they're withholding payment because something wasn't right. Maybe the job took longer than expected. Maybe they thought the price would be lower.
What works
Ask directly. "Is there something about the job you weren't happy with? I want to make sure we get this resolved." If there's a legitimate complaint, fix it. Don't argue over text — get them on the phone.
They never intended to pay
Rare, but it happens. Some people book service with no intention of paying. They dodge calls, ignore texts, and hope you'll give up.
What works
Nothing friendly will work here. After Day 21, send a formal final notice and follow through with collections or small claims. Don't waste time chasing someone with no intention of paying — cut your losses and move on.
What to say (and what not to say)
"Following up on the invoice from last Tuesday."
"Is there anything I can help with to get this wrapped up?"
"Let me know if you'd prefer to split this into two payments."
"I need to close this out by Friday. Can we make that work?"
"Your payment is past due and must be received immediately."
"I did the work, you owe me."
"I'm going to leave a bad review if you don't pay."
"I know where you live." (Plumbers have said this. Don't.)
The goal is to sound firm but not threatening. You're a professional trying to close out an invoice, not a debt collector trying to intimidate someone into paying.
When to involve a collections agency
Collections agencies take a percentage of what they recover — typically 25–50% depending on the age of the debt and how hard it is to collect. That means if you're owed $1,200 and the agency charges 30%, you'll get $840 if they successfully collect.
The invoice is over $500 — anything smaller and the fees eat too much of the recovery.
You've exhausted all friendly follow-ups and the customer is ignoring you.
You don't have time to chase this yourself or file in small claims court.
The invoice is under $300 — you'll spend more time and money than it's worth.
The customer is communicating and seems willing to pay, just slow.
The customer is genuinely broke — collections can't extract money that doesn't exist.
A warning about collections
Once you send an invoice to collections, you're burning that customer relationship forever. They will never call you again. They will tell their neighbors not to call you. Only escalate to collections if you're certain the relationship is already dead and the money is worth more than the reputation hit in your local area.
Small claims court: is it worth it?
Small claims court is designed for exactly this situation — disputes under $5,000 to $10,000 (depending on your state) where hiring a lawyer doesn't make sense.
- 01
File a claim at your local courthouse — usually a $50–$100 filing fee.
- 02
Serve the customer with court papers — hire a process server for $50–$75.
- 03
Show up to court with your invoice, text messages, and proof you did the work.
- 04
If you win, the court orders the customer to pay — but collecting is still on you.
The reality: winning a judgment doesn't mean you get paid. It means you have a legal right to pursue payment through wage garnishment or bank levies. Many plumbers win in small claims and still never collect because the customer has no money or hides their assets.
When it's worth it: the customer owns a home, has a steady job, and you're confident they have the money but are just refusing to pay out of spite. A court judgment gives you leverage.
When it's not worth it: the customer is broke, unemployed, or renting. Even if you win, you can't garnish wages they don't have or seize assets they don't own.
"The best time to handle unpaid invoices is before they happen. Require a deposit on jobs over $500. Send the invoice immediately. Follow up within 3 days — not 30."
How to avoid unpaid invoices in the first place
The plumbers who rarely deal with non-payment didn't get lucky with better customers. They built systems that prevent the problem before it starts.
Require deposits on larger jobs
Anything over $500 gets a 50% deposit before you start. This filters out customers who aren't serious and ensures you're not eating the full cost if they disappear.
Send invoices immediately
Don't wait until the end of the day. Don't wait until you get home. Send the invoice from the job site the moment you mark the job complete. The faster you invoice, the faster you get paid.
Use payment links, not manual bank transfers
If a customer has to log into their bank, find your account details, and manually send a transfer, there's friction. Friction creates delay. Delay creates forgetfulness. A payment link takes one tap.
Follow up early and often
Day 3, Day 7, Day 14. If you're waiting 30 days to follow up, you've already lost. The customer has moved on. The urgency is gone. Follow up while the job is still fresh in their mind.
CashWrench tracks unpaid invoices and sends payment reminders
Every unpaid invoice shows up with a red "Overdue" flag. Tap the invoice, tap "Send Reminder," and the customer gets a text with the payment link. Track exactly who owes what and when the last reminder was sent. CashWrench also lets you require deposits before starting a job — set the percentage (25%, 50%, 100%) and the customer can't confirm the job until they've paid.
1 tap
to send a reminder
50%
deposit on big jobs
0
spreadsheets
Two months free. No card. No catch. Try it at cashwrench.com or email contact@cashwrench.com
Unpaid invoices are part of the business. They happen. But they don't have to happen often, and they don't have to turn into months-long nightmares. Follow up early. Keep it professional. Escalate when you need to. And build systems that make non-payment harder in the first place.
— The CashWrench Team
Want to stop chasing money entirely? Read: The $17,500 sitting in your customers' bank accounts →
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