Connecting a booking system to accounting via API integration: What is it and how much does it cost?

We set up a similar integration for our car rental business in Abu Dhabi last year. They billed us a one-off 14,000 AED, and we agreed on 800 AED for monthly maintenance. Within the first three months, our staff's two hours of daily data entry completely vanished, and accounting errors dropped to zero. It paid for itself within 5 months.

A monthly maintenance fee of 1,500 AED sounds unnecessarily high to me. Once an API is set up properly with clean error handling, it runs smoothly for months unless one of the platforms makes a radical infrastructure change. Why keep paying the agency a fixed amount every month for nothing? Ask for a per-incident or hourly rate model instead.

Grab the API documentation for both systems and hand it to the developer. Can the booking side trigger webhooks? Does the accounting side support REST architecture? If either software lacks ready endpoints, the agency will have to build services from scratch, which is probably why you got that 18,000 AED quote. Confirm this with tech support on both sides beforehand.

Get them to map out the data flow diagram before signing the contract. 1) Will a refund slip be issued in accounting when a customer cancels? 2) How is the taxable base handled when a discount code is applied? 3) What happens to queued data if the system crashes? If you don't include the answers to these three questions as specifications in the proposal annex, they'll come back asking for extra dev fees down the road.

manual entry with 50 transactions a day is basically suicide anyway. one employee adds an extra zero by mistake and the penalty or tax difference will dwarf whatever the agency charges. imo negotiate them down to around 15k aed and get it hooked up right away, but switch that monthly retainer to an annual maintenance package.

To use this API thing, does our accounting software need to be left running on an open computer all the time or does the system handle everything automatically in the cloud in the background?

We recommend strictly defining the boundaries of responsibility between parties during the contract phase. In particular, whether customer credit card or identity information will be stored on a third-party intermediary server must be reviewed under UAE data protection legislation, and end-to-end encryption must be mandatory during data transfer.

The biggest headache I've seen in these kinds of integration projects over the years is both software vendors blaming each other once it's done. Your accountant says the agency is sending the wrong parameters, and the agency says the accounting service isn't responding. Make sure your agreement with the agency guarantees joint acceptance testing and at least 30 days of free support post-launch.

Correct in theory but it doesn't work that way in practice. I mean start with a small trial; don't commit to everything at once.

Correct me if I'm wrong.

It's rare to find an explanation this clear.

You're right, I've been down that road too. Start with a small trial; don't commit to everything at once.

Code without setup documentation isn't yours, even if you have it. That's all, sorry if I went on too long.

Do you think this works at any scale? If it's your first time, start small; scaling comes later.

If I were you, I'd go this route.

Sorry but this doesn't apply in every case. People defend habits, not processes. anyway resistance comes from there.

Start with a small trial; don't commit to everything at once. This is my opinion, I'm not claiming it's absolute truth.

You're right.

I completely agree. Mistakes made on the API integration side are usually reversible but expensive.

I went through the same thing. Any unwritten clause becomes a point of disagreement later, as both sides remember it differently.

Proven by experience.

There's a common mistake people make when doing this. The cheapest quote is usually the least thought-out one.

Correct me if I'm wrong.

Just a heads-up. The system lives on after delivery; maintenance is a separate line item.

If you post the result here, it will help others too.