Hotel Booking API: What OTAs Should Know Before Choosing

If you run an online travel agency, the hotel booking API behind your search box decides more than most people realise: which prices your customers see, how fast they see them and whether a booking actually goes through. On the surface, booking a hotel looks simple. You search, you click, you pay. Behind that sit legacy systems, mismatched data, timeouts and constant updates.

Mrigendra (Boney) Mittal, co-founder and CRO of Zentrumhub, has worked on exactly that problem for OTAs since 2021. His company sits between online travel agencies and hotel suppliers and normalises their APIs into one feed. In his view the hard part is not connecting to suppliers. It is making all of their differences invisible to the traveler.

Why a hotel booking API is harder than it looks

Every supplier, Mittal says, speaks a slightly different language. One sends rates in euros, another in dollars. One updates inventory in real time, another in batches every few hours.

“Some APIs are very well documented where others feel like they were written in the nineties and never updated.”

Mrigendra (Boney) Mittal, 1:34

As an OTA you do not just connect to these sources. You have to turn them into a single clean experience for your customer, and in his experience the complexity grows with every new integration. When a booking fails because one connection broke, he sees it as more than lost revenue: it damages trust. The traveler does not care which supplier timed out. They want the cheapest, most accurate total, instantly.

The failures are often small. In the early days, he recalls, some supplier integrations broke around a hundred times a week, and he remembers fixing problems with his team at 3 a.m. In one case a hotel in Bali stopped showing up in results. There was no error. The cause was a time zone mismatch in the supplier's API.

“Look at minute details in every API because every supplier talks in a different language, different contract.”

Mrigendra (Boney) Mittal, 27:45

The lesson for any team working on hotel connectivity: treat it like plumbing, where one tiny detail can ruin the whole experience.

Why speed decides conversion

Travelers searching for a hotel juggle several tabs, Mittal points out. They compare rates on Google and read reviews on TripAdvisor. If your results load four or five seconds slower than a competitor's, the customer is already gone, and that is lost revenue, not just a technical lag.

The difficulty is that suppliers respond at very different speeds: one in two seconds, another in five, another in ten. A good hotel booking API absorbs that difference so the traveler sees results right away. Zentrumhub aims for search responses under 500 milliseconds. He cites a Google travel study that found a one second delay in loading a page can reduce conversion by 20%, and argues that in hotel bookings, where margins are thin, that gap separates a successful OTA from the rest. Teams working on revenue management in the hotel industry watch those same margins closely.

Do less, but better

For years, Mittal says, the travel industry measured innovation in features: more dashboards, more modules, more integrations. In his view that often creates friction. Agents juggle five different logins, operators spend their time on manual reconciliation and travelers face too many choices and too many clicks.

“Travel tech does not need to do more. It needs to do less, but better.”

Mrigendra (Boney) Mittal, 13:51

His alternative is technology that becomes almost invisible. Instead of a dozen steps, the traveler needs three clicks: choose the hotel, book the room, confirm the payment. Offering alternative payment methods keeps that last step smooth. He points to Booking.com as an early adopter of A/B testing at scale, concluding that relevant content and relevant prices matter more than extra features.

How to choose a hotel booking API provider

Mittal's starting point is a clear division of roles. An OTA should not try to be a tech company, and a tech company should not try to be an OTA. For a new or midsize OTA choosing its B2B travel tech stack, he names these criteria:

• Know your role. Focus on relationships with travelers, curated experiences and driving bookings.
• Demand transparency. Travelers hand over money for a dream holiday, so data, pricing and integrations should have no black boxes.
• Plan for scale. Patching in one supplier here and another there creates spaghetti that turns into a mess once you grow.
• Look for experience. A provider that has worked with dozens of clients has already met the problems you will run into.
• Start small. Begin with five to seven suppliers, learn which cities and hotels people search for, then add supply.
• Test the technology and the support. Ask what traffic the platform can handle and whether someone will help at 2 or 3 a.m.

That last point matters more in B2B than many expect. When something goes wrong, the traveler calls the agent and the agent calls you, often from another part of the world. Hotels know this too: a hotel call center is often where bookings are won or lost.

Build or buy: launch first, then learn

Building a booking platform yourself can take a year or two, Mittal says, and by then traveler behaviour may have moved on. He prefers a build-versus-buy approach in which the technology already exists and the OTA goes live quickly. One client signed on a Friday and went live on the Monday. Without customisations, three days is possible; one week is the standard promise.

He compares launching an OTA to cooking a dish for the first time. You do not judge it yourself; you let your customers taste it and improve from there. Until you know what travelers want, you cannot know whether your website is right, so waiting for perfection carries a real opportunity cost.

Transparency and AI in hotel booking technology

Most OTA founders are not engineers, Mittal notes. When something breaks they do not want jargon; they want to know what went wrong, how it can be proven and how it gets fixed. His answer is to open the books: partners get access to booking logs, source data and supplier responses, so they can see exactly what came from which supplier and in which format.

On AI, he is measured. The first step is not adding shiny features but building adaptability into the business. With a platform that handles more than three million bookings a year, the data can power better recommendations: instead of a thousand hotels in Dubai, show the right handful. He sees AI supporting travel agents, not replacing them: it sorts and recommends, the agent adds the human touch.

His picture of the future is technology that makes booking a room feel as simple as ordering food: show a traveler five relevant hotels based on their history and let them choose, pick and book. You can watch the full conversation or explore more episodes in the Travel Commerce Unfiltered series.

Frequently asked questions

What is a hotel booking API?

It is the connection through which an online travel agency pulls rates and availability from hotel suppliers and sends bookings back. Because each supplier handles currencies, inventory updates and documentation differently, that layer has to normalise everything into one consistent feed, so the traveler sees a single, clean and accurate search result.

How fast should hotel search results load?

Mittal's platform aims for responses under 500 milliseconds. He argues that a traveler comparing several tabs will leave if your results arrive four or five seconds after a competitor's, and he cites a Google travel study linking a one second delay to a 20% drop in conversion. The booking layer has to absorb slow suppliers so results still appear instantly.

Should an OTA build or buy its booking technology?

In Mittal's view an OTA should focus on selling travel and leave the technology to a specialist. Building a platform yourself can take a year or two, while a ready platform can go live within a week, and in one case in three days. Launching early lets real bookings show you what travelers actually want.

What should you ask a hotel API provider?

Ask how much traffic the platform can handle, how it scales, and whether support is available at any hour, because problems surface in the traveler's time zone, not yours. Ask for transparency as well: access to booking logs, source data and supplier responses, so you can see what came from which supplier and why a booking failed.