I am looking at a few options to handle UK mail. 

 

Ideally I would use a mail handling service which provides an address that would be recognized by my existing UK banks, credit card holders etc to avoid any issues with not having a UK registered address. 

 

Does anybody have any experience with theses types of services?

- are they reliable?

- is the address they provide recognized by Uk banks etc as acceptable?  

- how do you provide proof of address?

 

any recommendations appreciated. 

Just use your Thailand address. 

In my experience UK banks are happy for me to use my Thailand residential address for most correspondence.  Some banks seem to need a UK correspondence address for sending cards to.  But all of them seem to insist on knowing where I actually live (am resident) and require to know that a correspondence address is only my correspondence address.

 

So, in response to the OP's questions,

"is the address they provide recognized by Uk banks etc as acceptable?"

 -  Maybe/probably, so long as they aware that it's a correspondence address.

"how do you provide proof of address?"

 -  You only need to provide proof of your residential address.  It's the only one that you can provide honest proof of.  Then you ask them to send correspondence to your mail handling service correspondence address.

There's at least 3 UK mail forwarding services easily discoverable using a google search. I had an account with one of them that worked well initially but due to the low volume of combined mail for their few Thailand subscribers, the best/cheapest option (bulk weekly mail via courier) was discontinued and the once-a-month individual options were easily (and more cheaply) substituted by using relatives back home using the Post Offices international mail services.