Can I give my Nanny/Employee a Cash Christmas Bonus?
Yes you can however it should be reported on the payslip and is subject to tax and national insurance.

Can I buy my Nanny/Employee a Present for Christmas?
Yes but if it cannot be counted as a ‘trivial benefits' you must report it to HMRC as it is classed as a benefit in kind.

What is a trivial benefit?
A trivial benefit is where all of the following apply:

• it cost you £50 or less to provide
  
• it isn't cash or a cash voucher
  
• it isn't a reward for their work or performance
  
• it isn't in the terms of their contract

You don't need to pay tax or National Insurance or let HM Revenue and Customs (HMRC) know about Trivial Benefits.