I'm currently on a double entry tourist visa after giving up work and letting my non-im B expire.

This (the tourist) runs out at the end of the year.

I intend to marry and apply for a marriage visa which I'll qualify for but my passport expires early next year.

Should I replace the passport before applying for the new visa?

Will my tourist visa stiil be available for the new passport if I do?

Yes, for practical convenience you should replace your expiring passport before obtaining a new visa.

You do not loose any visa validity in doing that.

You can also convert your tourist visa to non-imm 'O' in Bangkok at least, without leaving country.

Edited November 1, 201411 yr by paz

Particularly if you're a Brit, the sooner you apply to renew your passport the better!

If you get below 6 months of validity you will not be able to enter any ASEAN country.

You should get your new passport now.

You will be able to use your your tourist visa by showing it in your old passport on entry.

Thanks.