Originally Posted by corporate-wage-slave

If you change the date, but keep the route identical, and assuming no changes to taxes (etc) it can just be revalidated, not reissued, and that's a fairly low-key process, so it may be that it would work via AY. I personally wouldn't do this since it may cause an issue if BA for whatever reason is made aware of the change. If it's more than 24 hours from departure, then BA's rule is that it goes to the issuing point (here BAEC as a travel agent) since the ticket is under their control.