How to get paid faster as a plumber: the $4,000 lesson
You replace a 50 gallon water heater on Thursday and reroute a drain line on Friday. The invoice goes out 19 days later because the receipts are in the truck. By then hot water is just normal to the customer. He has spent two paychecks, and he says he will take care of it. He does not.
You have already paid for the heater, the helper and the gas. You are a $4,000 lender to a man who thinks of you as a bill. The fix is not a tougher collections letter. It is closing the gap between the job and the invoice, which is the first job of AI for plumbers.
Invoice from the truck, before you leave the driveway
Send the invoice while you are still in the driveway. Most field service and invoicing apps can do it: snap the parts receipt, tap the line items, hit send. The customer gets the bill while the memory of the leak is fresh and the gratitude is real.
If you still hand-write, photograph the invoice and text it before you drive off. The point is not the app. The point is the timing. Then make paying easy with a card reader or a pay link in the text. Many plumbers who switch find most residential customers pay before the truck leaves.
Every day between the job and the invoice, the customer forgets a little more why they owed you.
Deposits and cards on file for the bigger jobs
For anything over a few hundred dollars where you buy parts up front, take a deposit. Half down is common for a water heater, sewer line or repipe, a third for labor-heavy work. It covers your parts and tells you the customer is serious. Put it in the written estimate and get a signature, even a tap on a phone: "50 percent due at scheduling, balance due at completion."
A card on file goes one step further. Your payment tool stores the card securely, the customer agrees in writing, and you charge the balance the day the work is done. Send a receipt every time. Property managers and landlords usually prefer it.
Let automation do the polite, relentless part
For invoices not paid on the spot, plumbing invoicing automation does the chasing. It does not feel awkward, forget or get snippy. A simple sequence: day 1, the invoice with a pay link. Day 7, "Hi Dan, just making sure the water heater invoice came through. Here is the link." Day 14, a note with the due date. Day 21, past due, and is there a problem you can help with? Day 30, a late fee will apply and a person will call.
Most invoicing tools set this up in a few clicks, and AI bookkeeping can write the messages so they sound like a neighbor, not a bank. Every message should name the job, include the pay link and offer a way to reach a human.
What you can charge, in general terms
Late fees and interest are allowed in most places, but the rules differ by state. Some cap the interest you can charge a consumer, and some require the fee to be stated up front. So put your terms and a modest late fee on every estimate and invoice before work starts, and never invent a fee afterward. If you are unsure, call your state contractor board or a local attorney. This is general information, not legal advice.
Mechanic's lien rights exist in every state for work on real property, but the deadlines are strict and the paperwork is particular. Do not rely on a lien for a $400 drain job. Do know it exists for the $12,000 sewer replacement.
When a person picks up the phone
Automation stops at day 30. Then you or your office manager call, to ask rather than demand: "Hi Dan, the water heater invoice is still open. Is everything working the way it should?" Often there is a real reason. They thought the warranty covered it, or they lost a job. Three monthly charges on a card gets you paid and keeps the customer.
If someone will not pay, small claims court handles most invoices under a few thousand dollars without a lawyer, a collections agency takes a cut and the headache, and the lien covers the big jobs. Keep every text, email and signed estimate. They are your proof.
How Shouldered handles this
Shouldered HQ is an AI back office for plumbing company owners, with Simon running the work across seven desks. Matthew at the Finance Desk sends the invoice the day the job closes, runs the day 7, 14 and 21 reminders with the pay link, and tracks deposits and cards on file. Tabitha at the Service Desk answers customers who reply with a question.
A person still approves every late fee, payment plan and refund, and the day 30 call is yours. Lien deadlines and anything legal go to your attorney. HQ launches to customers in December 2026. See what it does for plumbing companies.
Try this this week
- Pull up your open invoices. Write down the total and the age of the oldest one. That is your number.
- Add two lines to your estimate template: a deposit amount for jobs over $500, and your payment terms and late fee in plain English.
- Set up a pay link or a phone card reader if you do not have one. Use it on your next job before you leave the driveway.
- Paste a five-step reminder sequence into a free AI chat tool and ask it to write the messages in a friendly, plain voice. Load them into your invoicing tool as automatic reminders.
- Call the oldest unpaid account yourself this week. Ask if everything is working. Offer a payment plan if they need one.
