I have just over 1M baht to pay over this year for my condo.

In the next few days I should have a Baht and Sterling account in BKK with HSBC (thanks for the advise chiang mai)

With the state of the pound right now I thinking of transferring more money than I need to complete the condo purchase, just to have some of my savings in a currency that is not pounds.

Thinking of transferring another 500,000 baht'ish.

Would there be any issues if this is in the same transfer (the transfer will be marked 'for condo purchase') as not all the money would be for the condo?

cheers

When you do the transfer of ownership as a non-Thai buyer, you must supply to the Lands Dept, originals of Foreign Exchange Transaction Form(s) whose baht amounts in total are greater than the transaction value being used for the transfer. This can be in one form or multiple forms. The excess value of the baht totals on those forms once supplied to LD are lost to you and cannot be reclaimed or used in another transfer transactions.

So yes, you can transfer in more foreign currency than you need. But it may be more judicious to break up the transfers into smaller amounts vs one big transfer if you intend on having several FETFs which can be divided up into several purchases.