bookings
What the Confirmation Has To Say
The confirmation is the only document most customers keep. Treat it as the contract summary it actually is and most booking disputes stop happening.
Ask a customer what they agreed to and they will not quote the terms page. They will scroll back to the confirmation.
That makes it the most consequential document in a booking system and the one most often generated by a template nobody has read since it was set up.
The six things it must carry
What was booked, in the customer's words. Not the SKU, not the internal service code. "Roof inspection and measurement" rather than "SRV-204".
When, with the time zone named. Day of week and date, both. "Tuesday 14 October, 9:00am (Mountain Time)" eliminates a whole class of confusion for one extra line. The day of the week matters more than it looks: people catch a wrong date by noticing it is a Tuesday.
Where, as an address that opens a map. And if it is at the customer's address, repeat the address you hold, because this is the moment a typo gets caught rather than the morning of.
Who is coming, and how long it takes. A name, even just a first name, changes the interaction at the door. A duration lets the person plan their day, which is the difference between a kept appointment and a rescheduled one.
What it costs, and what is due when. Including the deposit, if one was taken, and the balance.
How to change or cancel, as a link, with the cut-off. One tap. This is the single highest-value element in the message and the one most often reduced to "contact us if you need to make changes".
Add the calendar attachment
An .ics attachment or an add-to-calendar link is worth more than any reminder you will send later, because it puts the appointment where the customer already keeps their commitments.
RFC 5545 defines the format and it is simpler than it looks for this purpose: a single VEVENT with a start, end, summary, location and description covers it. Two details separate one that works from one that does nothing.
Use a stable UID for the booking, and increment SEQUENCE when it changes. That is what lets a later update move the existing entry rather than creating a second one, which is how customers end up with three copies of the same appointment.
Write the time with its time zone, not as a floating local time. A floating time is the appointment in whatever zone the customer's device happens to be in, which is correct right up until they travel.
Send it immediately
Within seconds, not within the next batch.
Silence after a booking reads as failure. A customer who does not see a confirmation within a minute will, in meaningful numbers, book again or book elsewhere, and the duplicate booking is now your problem.
If the message genuinely cannot be sent, the on-screen confirmation has to carry everything the email would have, because that screen is now the only record the customer has.
The commercial sentence that changes what it is
A confirmation is transactional. That is a category with its own treatment, both legally and at the mail providers who decide whether it reaches the inbox.
Adding a promotion changes the character of the message. The FTC's CAN-SPAM compliance guide sets out how the primary purpose of a message is assessed and what obligations attach to commercial content, including the unsubscribe mechanism and the physical postal address.
The practical reading for a booking confirmation is to keep it transactional. The marginal revenue from a promotional line in a confirmation is small. The cost of having every confirmation reclassified, and of a customer unsubscribing from the thing that tells them when you are arriving, is not.
Update the same way
When an appointment moves, send the same document again, complete, with the change stated at the top.
Not "your appointment has been updated". The full confirmation, with one line saying what changed: moved from Tuesday 9am to Thursday 2pm. The customer should never have to compare two messages to work out what is true now.
And update the calendar entry with the same UID, so their diary moves instead of accumulating.
The test
Open the last confirmation your system sent. Read it as somebody who booked three weeks ago and has forgotten everything.
Can you tell what you booked, exactly when, exactly where, who is coming, what it costs, and how to move it, without opening anything else or asking anybody?
If not, every one of those gaps is a phone call your office is taking, several times a week, forever.