My (Thai) wife and I (UK citizen) are currently living together in BKK.

 

We plan to visit UK over the Christmas period.  We have a house together in the UK and will spend time there and also with my family in their house.

 

Should I provide a letter from my family confirming that we can indeed stay with them? I see no mention of this in the official guidelines but my wife is keen to provide it.

 

To be clear, I or my family will not be "sponsoring" her in a financial sense, she works full time in a good job.

 

If it is relevant, my wife has lived and worked in UK for several years in the past.

 

Thanks!

I doubt it would be necessary if you are also staying in your own home in the UK.  That said it wouldn't hurt to have an invitation from the folks.  I had a letter from my mum on every trip except when we went back as a surprise for her 70th birthday.  For visit visa's I'd always be very clear with details (our situation, brief history, intended plans for visit etc) in the sponsor's letter - even if you are technically not sponsoring financially you will, as her husband, be part of the application ????

Yup, I always include a letter from me. As stated above, just a brief out line of our travel plans, reasons to return to Thailand and that I can cover any unforeseen expenses. Just applied last month for our Xmas trip, no issues at all.