Why does the price sometimes change between the search results and the payment page on my booking site?
Yes, it can happen, and it is normal rather than a fault in your website. The price shown on a search results page comes from a cached or a quoted response from the supplier, and the price at checkout is a fresh check against live inventory at that moment. Between those two moments the airline or the hotel can withdraw the fare, sell the last room at that rate, or change the tax and fee breakdown, and your portal has to show the traveller what is actually bookable now.
How often it happens depends mostly on the supplier and the product. Flight fares move faster than hotel rates, and low cost carriers reprice more aggressively than a normal published fare. If you are pulling from several suppliers at once, a slow one may return a stale price that a later check corrects. Nothing in the portal can stop the supplier from repricing, so the honest fix is to make the message clear and to show the new price and the difference plainly before asking the customer to continue.
What you can control is how long a search result is held before it is refreshed, and whether the customer sees a warning or is silently moved to a new price. Silently changing the amount is the fastest way to lose trust and to invite a chargeback later, so it is better to pause, tell them, and let them accept or go back.
If it is happening on almost every booking rather than occasionally, check your cache timing and which supplier the affected results are coming from, because that usually points to one connection rather than to a general market problem.
