Gift from mother

My wife has recieved a cash gift of GBP 4000 from her mother while she was visiting us in the UK. She has deposited the amount in her bank. Does she need to pay tax on this amount? if not what kind of documentation / record needs to be maintained by her to present to HMRC in case this amount in queried later.

Hi,
There are generally no Income Tax implications on the giving of or receipt of a cash gift unless the cash gift generates interest or dividends.
These would then potentially be subject to tax.
Further guidance can be found here:
Tax on savings interest 
Tax on dividends 
Thank you.