For most rental businesses, the website is where bookings are won or lost. The practical goal is simple: customers should be able to choose dates, see available vehicles, and place an order without calls, screenshots, or “we’ll confirm later” friction. On the business side, the same booking must land in the back office with the right dates, vehicle group, extras, and customer details.
That’s what car hire booking software is typically used for: keeping availability and orders consistent across the website and internal operations.
Three common integration paths for online reservations
1) WordPress plugin (for WP sites)
A plugin approach is usually the fastest route when the site is on WordPress. The RentSyst WordPress plugin description includes fleet/group synchronization and website booking components.
2) iFrame embed (for almost any CMS)
An iFrame is a copy-paste embed: you place a code snippet on your page and display a ready booking form. RentSyst describes iFrame integration in this “copy the code and paste it where you want the order form” format.
3) API integration (for custom UX and deeper control)
An API path is used when the business wants a custom booking experience (custom pages, custom layout, bespoke steps) while still connecting to the same reservation logic. In the RentSyst flow, API integration is described as a way to embed needed fragments of the system on a site.
What an API enables in practice
An API is an application programming interface that lets a website communicate with the server to access data and perform actions, expanding what the website can do for the customer.
That’s why teams choose a car rental API when they need:
- a fully branded booking journey instead of a standard embedded form
- custom search, filtering, and availability pages
- specialized booking steps (for example, different flows per location or vehicle class)
- tighter connections to internal tools and partner processes
A typical API-driven reservation flow (high level)
A common implementation pattern looks like this:
- Search & availability: the site requests available vehicles/groups for dates and pickup parameters.
- Pricing display: the site shows base price + extras and calculates an estimated total.
- Order creation: the site submits customer details and selected options to create a reservation.
- Confirmation screen: the site displays booking status and next steps (payment, documents, support).
- Post-booking updates: the site can retrieve booking details for “My booking” pages or email triggers.
This approach keeps the user experience native to your website while still relying on the reservation backend.
What to prepare before integrating bookings
To avoid rework, define these basics first:
- Fleet structure: which vehicle groups/classes are bookable online, and which are request-only.
- Availability rules: lead time, buffers between rentals, blackout dates for maintenance/cleaning.
- Pricing rules: minimum rental period, seasonal pricing, mileage limits, extras, deposits, delivery/collection fees.
- Customer data: what’s required at booking (name/phone/email), and what can be collected later (driver license details, address).
- Checkout logic: when the booking is considered “confirmed” (immediate vs pending).
- Pages and tracking: where booking lives (dedicated landing vs navbar), and which conversion events you’ll measure.
Choosing between iFrame/plugin vs API
A simple rule:
- pick plugin/iFrame if you want a fast launch with minimal development and a standard flow;
- pick API if you want the booking UX to be native to your site, controlled by your code, and adaptable as you scale.
RentSyst lists WordPress plugin, iFrame, and API as parallel options for online reservation integration.
Implementation expectations and reference
RentSyst’s API integration page mentions fast integration (up to 5 minutes), free help from specialists, and SSL encryption for data protection.
The same page links directly to the API documentation, which should be the source of truth for endpoints, authentication, and implementation details.
Written by : Carlo Di Leo
At the age of 24, with no experience in the security industry or any money in the bank, Carlo quit his job and started Spotter Security from his parent's basement. Founded in 2004, Spotter grew from a single man operation into a multi-million dollar security system integrator that caters to businessess and construction sites across Canada.
