Q I am going to Thailand in a couple of weeks. Is it best to change currency here or take sterling there to change?
A Take sterling. As a rule of thumb, there are currently 50 Thai baht to £1 - but that is the rate that applies to very large transactions. For holidaymakers exchanging a few hundred pounds, the rate is less favourable. For example, order online from the Post Office today and you will get a rate of around 46.5 baht to the pound.
You may wish to obtain a few thousand baht in advance to cover initial expenses, but personally I would always wait until I arrived in Thailand. Airport bureaux de change in Thailand generally offer better rates than any UK provider; I would take sterling notes, change perhaps £50 at the airport, and wait until I was in central Bangkok, Chiang Mai or at a resort before exchanging more.
If you happen to have some US dollars left over, it is worth taking them in case of emergency in the back end of beyond. Although the Thai baht is no longer tied to the $, American money is still the most recognised foreign currency - so you should always find someone willing to change $10 or $20. The same cannot be said for sterling.