Booking API Allows Double Bookings? Start Here
Check why two different bookings get the same slot. Separate an old availability result from the final rule that accepts or rejects an appointment.
Two people can see the same free slot and both try to book it. Checking the diary first does not reserve that slot. Another booking can arrive before the next request saves. This is different from one request creating two copies. Here, two valid requests compete for one place, practitioner or room. Your integration needs a clear rule for which booking is accepted.
Things to check first
- Check which diary is the final authority. A Google Calendar event may only be a copy of the clinic booking. A free calendar slot does not prove that the practitioner, room and treatment are all available.
- Check the appointment length, buffers, business location and practitioner. An availability query using the wrong treatment or location can return slots the customer should never have seen.
- Ask the vendor what happens when two create requests reach it together. Does it reject a clash, reserve a slot or allow overlaps? Do not assume an API blocks double bookings because the public booking form does.
Cliniko lists booking-related API actions in its reference. Check the exact create and availability rules before promising that an integration can prevent clashes. This shows documentation, not a live clinic diary.
Documentation screenshot: Cliniko. Example screen; yours may look different.What to ask the freelancer to do
- Check the vendor booking and availability rules
- Define practitioner, room and buffer checks
- Test two requests competing for one slot
- Explain any limit that needs staff confirmation
Questions to ask before hiring
- Does the booking API itself reject a clash?
- Can your fix cover bookings made by reception too?
- What will the customer see if the slot is taken just before saving?
Red flags
- Treats an availability lookup as a reservation
- Tests requests one after another instead of together
- Promises no clashes without checking the vendor API
Agree what the job includes
- Write down what uses a slot: a practitioner, room, piece of equipment or a combination. Include treatment length and cleanup time. State whether staff are allowed to make exceptions manually.
- Check availability close to the final booking step, then use the vendor's supported way to accept or reject the booking. Cliniko's available-times API follows online-booking settings. That is useful, but it is not proof that the result reserves a slot.
- Test two requests for the same slot at once, including one from another booking channel. A lock inside your own app cannot control a separate receptionist or vendor website unless they use the same booking rule. If the API cannot enforce the rule, offer a request-to-book flow or the vendor's own booking page.
What to send the freelancer
- List every place appointments can be made: reception, website, booking app and phone assistant. Name the diary staff actually work from.
- Give the developer made-up treatments, rooms and practitioners in a test account. Include a short visit, a long visit and an existing blocked slot.
- Get the vendor's API documentation and written answers about clashes, slot holds and any booking permissions your plan needs.
How to check the work is done
- For a slot that allows one booking, two competing test requests cannot both show a confirmed booking. The losing request offers another time or a clear next step.
- Tests cover buffers, another booking channel, the wrong room and a slot that becomes busy after the customer selects it.
- The handover explains any clash the vendor cannot prevent and when staff must confirm a request themselves.
What may cost extra
- Changing the clinic's staffing rules, adding rooms and replacing the booking system are separate jobs.
- A developer cannot promise a slot hold or booking lock that the vendor API does not provide. Any workaround must state what it cannot protect.
Sources checked 23 October 2026
Use this guide to agree the work and check the result.
Common questions
Is double booking the same as a duplicate booking?
No. A duplicate is one booking saved twice. A double booking is two separate bookings accepted for the same limited slot. They need different tests and may need different fixes.
Can I use Google Calendar as the availability check?
Only if its contents and rules match the service you sell. A clinic may also need practitioner, room, treatment and buffer checks. Confirm where the final booking decision is made.
Find help on Fiverr
Ready to hand it over? This freelancer offers help with the job covered in this guide. Look at their work and send them your brief to get a quote.
EJaz
@iiijaz · FiverrBooking API integration review
This listing includes booking-platform integrations in PHP, Laravel and WordPress. Ask EJaz to check your vendor’s booking rules first. We have not verified work on your clinic software.
The listing showed 210 reviews when checked. Reviews cover a range of jobs; they do not prove experience with your clinic software.
Before you hire: Ask whether the vendor itself rejects slot clashes and how two competing requests will be tested. Do not order on a promise alone.
View service on Fiverr ↗Listing checked 2026-10-23. We have not hired this freelancer or tested their work.
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