Slightly OT but may be of interest to others this is something I Iearnt a while back.

If it is a BA Holiday package booking you can usually* change the names for a small fee if you are an EU resident but if you are a non EU resident then it's treated differently.

7.4.5. If you are a resident of the EU purchasing a Package, you are allowed (under the European Directive of Package Travel, Package Holidays and Package Tours 1990) to amend individuals' names, subject to an amendment fee, and any additional charges made by the suppliers of the services (e.g. airline, hotel, car rental company, experience provider or transfer provider) to make the changes, which will be advised at time of enquiry. Any changes of the individuals named in the booking are conditional on the substitute individual accepting these booking conditions and otherwise satisfying all the conditions applicable to the Package. Name changes within 48 hours of departure are not guaranteed.

7.4.6. If you are not a resident of the European Union, we do not permit name changes. This means any name change is treated as a cancellation and rebooking, and as such the cancellation charges as advised at time of booking will apply (see Clause 7.6).

7.4.7. Alterations to your airline ticket will be dealt with in accordance with the relevant airline's conditions of carriage and all relevant ticket conditions.

*Please note that some types of tickets may be non-refundable and non-changeable.

https://www.britishairways.com/en-gb...and-conditions