What are the rules about entering Thailand with two passports, a valid SETV in an old passport and a renewed passport from the same country. UK in this case. Thank you
TLDR : Answer Summary
When entering Thailand with two passports, one being an old passport that holds a valid SETV (Single Entry Tourist Visa) and the other being a new passport, the process is generally straightforward. You should present both passports at immigration. The authorities will likely stamp your new passport but recognize the visa in the old one. Ensure that your old passport is not canceled; if it is valid, presenting both should not pose any issues.