Hi guys, quick question. UK passport holder. I'm planning on spending 6-8 weeks in Thailand at the start of the new year and I have my single entry tourist visa for 60 days ready. There's a chance that after the first week I may have to pop over to Cambodia for a few days. My question is that if I enter Thailand the first time, even though I have a tourist visa ready in my passport, can I choose not to use it, get the standard 30 day stamp on arrival, then when I enter the second time on my way back from Cambodia use my tourist Visa then?