An invoice has one job: make paying it the easiest available option. Most of what follows exists to remove a reason to delay.
The fourteen elements
Your business
- Business name and trading name if they differ. The name on the invoice should match the name on the payment they are about to make.
- Address, phone and email. A real address, not just a mobile number.
- Licence number where your state requires it. Some jurisdictions require it on every invoice, not just estimates.
- Tax registration number if you are registered.
The customer
- Who is being billed. Not always who was at the property. Landlords, property managers and home warranty companies are all common.
- The service address, which is frequently different from the billing address.
The document
- The word "Invoice". Obvious, and it is what makes it distinguishable from an estimate in an inbox.
- A unique invoice number, sequential and never reused.
- Date of issue, and the date the work was done if they differ.
- Due date, as an actual date. "Net 14" is jargon; "due by 12 October" is not.
The work
- What you did, in language the customer recognises.
- The amounts, with tax shown separately where it applies.
Getting paid
- How to pay. All methods you accept, with a link if you have one.
- Warranty, split between equipment and your labour.
The description line is where invoices get queried
This is the part most worth getting right, and the part most often reduced to two words.
| Weak | Better |
|---|---|
| Plumbing work | Diagnose and repair leak on cold supply under kitchen sink |
| Service call | Emergency call-out, Sunday, diagnose no hot water |
| Parts and labour | Replace 50 gallon gas water heater, including expansion tank, pan and haul away |
| Drain work | Clear blockage in main sewer line from cleanout, camera inspection included |
A customer querying an invoice is nearly always querying a description they cannot connect to something that happened in their house.
Itemised or grouped?
Same trade-off as on an estimate, with one difference: after the work, a customer who was surprised by the total will want the breakdown, and refusing looks bad.
The practical approach is grouped scope with detail available. "Water heater replacement, including all parts and disposal, $2,225" on the invoice, and a full breakdown you can send within the hour if asked.
Call-out and diagnostic fees
Show it as its own line, and state on the invoice whether it was credited against the work. The most common invoice dispute in plumbing is a customer who believed the call-out fee came off the repair and finds it added to it.
If your policy is to credit it, show it as a line and then as a deduction. Seeing it applied is worth more than having it silently absent.
What gets left off and should not be
The due date as a date. Terms nobody reads are terms nobody follows.
Tax shown separately. A single total with tax buried inside is harder for a business customer to process and can cause a delay at their end.
What the warranty covers. Customers assume the manufacturer's tank warranty covers your labour. It does not, and the time to establish that is now.
A reference they can quote. If your invoice number is the only reference and it is small print at the bottom, expect payments you cannot match.
What to leave off
Your cost. Obvious, and it occasionally escapes when a price book is exported carelessly.
Apologies for the amount. If the price was right, it does not need softening. If it was wrong, the invoice is the wrong place to discover that.
Threats on a first invoice. Late fees can appear as terms. "Failure to pay will result in" language on day one reads badly to a customer who was always going to pay.
The free invoice generator lays out all fourteen elements and prints to PDF. If you want to check the underlying rate is right before you bill it, the labour rate calculator works back from what an hour actually costs you.
General guidance, not tax or legal advice. Invoice requirements, licence display rules and tax treatment vary by state and by whether you are registered for sales tax.
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