Hi:

I have an offer of a rental arrangement with a Thai who is living in London. She's a lifelong friend and the arrangement involves me renting her appartment from her and paying her the rent via direct debit (probably from my UK account, to her UK account). She owns the appartment outright with no outstanding mortgage or loans.

Are there any formalities required to satisfy the Thai authorities?

I will be living there indefinately and abiding by the required visa, WP procedures etc.

Thanks.

AFAIK, Just inform Immigration at Suan Phlu where you are living.