If my customer's name is spelt wrong on a flight booking, can I fix it on my portal myself?

Usually no, not as a direct edit you make yourself, because the name on a ticket belongs to the airline record and not to the booking software. Once a booking is made and the ticket is issued, the passenger name is locked in the airline's system, and no travel portal can quietly overwrite it. What your portal can do is let you find the booking and raise an amendment or correction request against it, which then goes to the airline through the supplier the fare came from.

Whether the correction is actually allowed depends entirely on the airline and the fare rule, so this is one area where we cannot promise an outcome. Many full service airlines will accept a minor spelling correction on the same passenger, sometimes free of charge and sometimes with a fee. Budget airlines often treat any change to a name as a new booking altogether. Some cheaper fare types do not permit corrections at all, and the only route left is to cancel and rebook, which can mean losing part or all of what was paid.

Timing makes a big difference too. If you catch the mistake before the ticket is issued, the chances of a clean fix are much better. After ticketing it gets harder, and once check in has opened or the flight has departed there is generally nothing anyone can do. This is also why a correction is not instant, as the portal has to wait on the airline's answer rather than confirming it for you on the spot.

The practical habit worth building is to read the name back from the passport before you confirm any flight, and if you do spot an error afterwards, raise the request the same day rather than leaving it until closer to travel.