as a uk passport holder I believe I have a 15 day visa exemption. I'd like to stay for longer so can I sort a visa out while in Vietnam or does it need to be done before?
For UK passport holder, you will have 15 days visa exemption. However, your previous trip must be far at least 30 days the next trips.
If you would like to stay over 15 days, you need to apply visa to arrive Vietnam.
If you did arrive Vietnam already and want to stay more without leave Vietnam, you should do extend the visa.
Any help, please feel free to contact with us.