Taking payment at the point of booking is the simpler model and, where it fits, the better one. It protects the slot and there is nothing to chase afterwards. But a lot of real work does not fit it. You cannot always name a price before you have done the job, and some clients cannot pay by card at all.
For those cases the invoice comes after the appointment. That is a normal way to run a service business, and it is manageable as long as the invoice goes out promptly, says the right things, and is generated by the system rather than by you remembering on a Sunday evening.
This article covers when post-appointment billing is the right choice, what has to be on the invoice, how to set payment terms, and how to chase late payment without damaging the relationship. For the alternative, see collecting payment at booking.
When Invoicing Afterwards Is The Right Call
Variable scope. If the price depends on what you find, guessing at the booking page helps nobody. A diagnostic visit, a repair, a consultation that might run long, or anything billed by time all price themselves at the end.
Third party payers. Where an insurer, a health scheme, an employer or a public body pays, the client's card is irrelevant. The claim goes through a process that needs documentation, and that process is an invoice.
Corporate clients with purchase orders. Larger organisations pay through accounts payable against a purchase order. There is often no card in the building. Insisting on payment at booking with these clients does not speed anything up, it just removes you from consideration.
Established retainer relationships. A client you see weekly does not want to enter a card each time. Bill monthly in arrears and both of you handle one transaction instead of four.
Add-ons decided during the appointment. If the final total routinely differs from the booked price, a deposit at booking with the balance invoiced afterwards is often the cleanest split. The deposit side is covered in deposits versus full payment.
The Cost Of Billing Later
Be clear about what you are taking on. Money arrives weeks after the work rather than before it, which is a cash flow cost. Some invoices will be paid late and a few will need real chasing, which is time you do not bill for. And the appointment loses the commitment effect that prepayment creates, so a booking with nothing paid is a booking that is easier to skip. If your no-show rate on unbilled appointments is uncomfortable, take a deposit at booking and invoice the balance rather than charging nothing at all.
| Charge At Booking | Invoice Afterwards | |
|---|---|---|
| Cash timing | Before the work | Weeks after the work |
| No-show protection | Strong | None, unless a deposit is taken |
| Fits variable pricing | Poorly | Well |
| Works with purchase orders and insurers | Rarely | Yes |
| Ongoing admin | Low | Higher: issuing, tracking, chasing |
What The Invoice Has To Contain
An invoice that is missing something gets parked in someone's inbox, and you will not be told. The parts that matter operationally:
- Your business name, address and contact details, plus any registration numbers your jurisdiction requires.
- The client's billing name and address, which is often not the same as the person who attended.
- A unique invoice number and the invoice date.
- The appointment date and a description of what was delivered. Vague descriptions are the most common cause of a query.
- Quantity, unit price and line total for each item, with any deposit already paid shown as a deduction rather than silently netted off.
- Any tax applied, shown separately. What you must charge and how it must be presented depends on where you operate and is a question for your accountant, not for a blog.
- The total due and the due date as a real date, not "30 days".
- How to pay, with the account details or a payment link, and a reference to quote.
- A purchase order number where the client has given you one. Corporate invoices without a PO number are frequently rejected on sight.
Send it as a PDF attached to an email that also states the amount and the due date in the body, because plenty of people never open the attachment.
Payment Terms That Get You Paid
Terms are a negotiation with reality. Shorter terms get you paid sooner only if the client's process can accommodate them.
For individual consumers, payment on the day or within seven days is normal and reasonable. For small businesses, 14 or 30 days is standard. For large organisations, your terms will often lose to their payment run schedule regardless of what you wrote, so find out when their run happens and time your invoice to catch it. An invoice submitted the day after a monthly run waits a full extra month.
A few practical points. Agree the terms before the work, not on the invoice, because an invoice is a poor place to introduce news. Invoice immediately, ideally the same day, since the connection between the work and the bill fades fast and late invoices signal that you are relaxed about payment. Offer the payment method that suits the payer, since a card link that speeds up a consumer is useless to a finance department that only makes bank transfers. And if you charge interest or a fee on overdue amounts, state it in the terms up front; whether it is enforceable where you operate is a question for your own adviser.
Chasing Late Payment Without Souring The Relationship
Most late payment is not refusal. It is an invoice that reached the wrong person, sat in a queue, or missed the payment run. Treat it as an administrative problem until proven otherwise and you will keep both the money and the client.
A sequence that works:
- Before the due date. A short, friendly note a few days out, confirming the amount and asking whether anything is needed to process it. This catches missing PO numbers and wrong addresses before they become lateness.
- Just after the due date. A polite reminder with the invoice attached again, assuming it was an oversight. Most payments arrive at this step.
- A week or two later. A direct message asking for a payment date rather than a payment. A date is easier to give, and it gives you something to follow up on.
- Pick up the phone. One call to accounts payable resolves more stuck invoices than another four emails, because it finds out where the invoice is.
- Formal escalation. A written notice of the overdue amount and the consequence, such as pausing future bookings. What you can do beyond that depends on your jurisdiction and contract and is a question for your own professional adviser.
Keep the tone the same at every step: matter of fact, no apology for asking, no accusation. Do not deliver more work for a client with a materially overdue balance, and do not stay silent for months and then arrive angry. Steady, unemotional follow-up is what gets you paid without costing you the relationship.
Automating The Invoice Off The Completed Booking
Manual invoicing is where this model breaks. The work happens, the day fills up, the invoice waits for the weekend, and the weekend is where invoices go to be forgotten. Every day of delay is a day added to your payment cycle.
The fix is to treat the completed booking as the trigger. Everything the invoice needs is already recorded: who attended, what service, how long, what price, and what deposit was paid. The pieces to automate:
- Marking a booking complete is what starts the invoice, not a separate decision.
- Client details, service, date and price come from the booking record rather than being retyped, which is also where most invoice errors come from.
- Any deposit already taken appears as a deduction automatically.
- Invoice numbers are sequential and assigned by the system.
- Reminders before and after the due date are scheduled, not remembered.
- Payment marks the invoice settled and stops the reminders, which is the step that most often goes wrong and irritates clients who have already paid.
Even without a full billing product, most of this can be wired together. appntmnts exposes bookings through a REST API and webhooks, so a completed booking can trigger an invoice in your accounting software with the client, service, date and amount already filled in. That turns invoicing from a weekly chore into something that has already happened by the time you think about it.
Choosing Per Service, Not Per Business
You do not have to pick one model for everything. The common arrangement is to charge at booking for fixed-price consumer services, take a deposit and invoice the balance where scope varies, and invoice fully in arrears for corporate and insurer-funded work. In appntmnts each appointment type carries its own price and payment setting, so those three can run side by side on one booking page.
Set the default to whichever fits most of your work, then make exceptions deliberately. The features overview covers payments and appointment types, pricing shows the plans, and if your billing sits in another system the integrations page is the place to start.