The Plumbing Owner's System for Getting Every Invoice Paid

The average plumbing company carries 12 to 18 percent of its monthly revenue in unpaid invoices at any given time. On a shop doing $800,000 a year, that is $8,000 to $12,000 sitting in someone else's pocket every single month.

Why Plumbing Invoices Go Unpaid in the First Place

Before you can fix the problem, you need to know which bucket each unpaid invoice falls into. In most plumbing shops there are three root causes.

Invoices That Were Never Sent

A technician closes the job and forgets to send the invoice from the field. Or he hands the customer a paper copy, and nobody enters it in the system. Industry surveys of service contractors consistently find that 5 to 8 percent of completed jobs are never invoiced at all. On that same $800,000 shop, that is $40,000 to $64,000 a year that walks out the door invisibly.

Invoices That Are Disputed

The customer says the tech quoted a different price, or the scope changed and nobody documented it. Without a signed work order or before-and-after photos attached to the invoice, you lose the argument even when you are right.

Invoices That Are Just Ignored

These are the most common and the most fixable. The customer received the invoice, has the money, and simply has not acted because nobody followed up. Studies on B2C and B2B service billing show that invoices with no follow-up go uncollected at a rate three times higher than invoices with a structured reminder sequence.

The Numbers Behind a Leaky AR Pipeline

That table is conservative. It uses the low end of each range. The point is that six figures of annual exposure is normal, not exceptional, for a shop with no formal collections system.

Build the System Before the Invoice Is Sent

Collect Payment Information at Booking

For residential work, capture a card on file at the time of booking. Tell customers plainly: "We keep a card on file and charge within 24 hours of job completion unless you request another method." This single practice eliminates the residential ignored-invoice problem almost entirely. Shops that move to card-on-file billing report residential collections going to 98 to 99 percent within one billing cycle.

Price in Writing Before the Wrench Turns

Every job needs a signed estimate or a signed work order with the price shown before work starts. For change orders, a text message from the tech with the customer's reply counts as written authorization. No signature, no scope expansion. This kills the dispute bucket before it forms.

Close the Job in the Field

Require techs to send the invoice before they leave the driveway. If your techs usefield service software, they can email the invoice directly from a mobile device while the customer is still standing there. Completion rate on same-day invoicing is dramatically higher than next-day or end-of-week invoicing because the work is fresh and the customer is satisfied.

The Five-Touch Follow-Up Sequence

For any invoice not paid on delivery, run this sequence without exception. Automate as much of it as possible. Consistency is the entire value.

What to Say at Each Touch

Touch 1: "Hi [Name], thank you for having us out today. Your invoice for [amount] is attached. You can pay online at [link] or call us at [number]." Touch 3: "Hi [Name], just checking in on invoice #[number] for [amount] due [date]. Any questions, reply here or call us." Touch 5: "[Name], this is [your name] at [company]. Invoice #[number] for [amount] is now 30 days past due. We need to resolve this by [date] or we will need to move forward with a mechanics lien filing. Please call me directly at [number]."

Late Fees and Mechanics Liens: Your Two Enforcement Tools

Late Fees That Actually Deter Delay

A 1.5 percent monthly late fee (18 percent annually) is standard and enforceable in most states. It must be disclosed in your original contract or on the invoice itself to be collectible. On a $3,500 invoice sitting unpaid for 60 days, that fee adds $105 and signals that carrying your debt has a real cost. The fee matters less as revenue and more as behavioral leverage.

Mechanics Liens for Larger Commercial Jobs

For commercial or larger residential jobs over roughly $2,500, a mechanics lien is your most powerful collection tool. Filing fees typically run $50 to $150 depending on county. The lien attaches to the property title, meaning the owner cannot sell or refinance until the lien is released. Most lien filings result in payment within 30 days because the cost to the property owner of leaving it unresolved is far higher than your invoice. Know your state's filing deadlines: most require filing within 60 to 90 days of last furnishing labor or materials.

The Daily and Weekly AR Routine

A system only works if someone runs it on a schedule. Assign one person, whether that is you, your office manager, or your dispatcher, as the AR owner. That person runs these checks.

Tracking the Metrics That Tell You the System Is Working

Three numbers tell you everything about your AR health. First: Days Sales Outstanding (DSO). Calculate it as (accounts receivable balance divided by average daily revenue). Average daily revenue for an $800K shop is $800,000 divided by 365, which equals $2,192 per day. If your AR balance is $35,000, your DSO is 16 days. Healthy for a plumbing shop is under 20 days. Aservice business CRM that connects to your invoicing will surface this number automatically.

Second: Collection Rate. Payments collected in a period divided by invoices issued in that period. Target 97 percent or better. Below 94 percent means your system has a leak. Third: Invoice-to-Close Time. From invoice sent to payment received. Track the median, not the average, because a few very late payers will skew an average. A median under 7 days is excellent. Median over 15 days means follow-up timing is too passive.

One Change You Can Make Before End of Day

Pull your current open invoices right now. Sort by age. Every invoice over 14 days gets a phone call today, not an email. Not a text. A call. Tell the customer plainly what is owed and ask when they can pay. That one action, on that one afternoon, will recover more cash than any software or process change you implement next quarter. The rest of the system keeps the problem from rebuilding. For plumbing shops that want the invoicing, scheduling, and follow-up automation running in one place,PrimeX Business Solutions was built specifically for that workflow.