We are flying TPA/LGW transport to LHR/VIE and return is same in reverse (tickets are roundtrip to VIE). So what country do I need to check as far as testing requirements? Do I need to fill out travel locator forms for London and Vienna? And do I need to comply with both locations regarding testing, and vaccinations? Our trip out puts us in the 12 hour window, the return flight does not.
We also have a roundtrip flight from VIE to ZAG.
So possibly will need to test before we leave, in VIE before we fly to ZAG, in ZAG when we return to VIE, and finally when we hit London B4 flying home? This seems excessive, but wondering if this is what is needed.