Remote worker NIN contributions

Good morning, I am a full-time employee of a British company, and I am planning to work remotely from Italy for 1 or 2 years. I have read that it's possible to continue paying National Insurance (NIN) contributions in the UK while only paying income tax in Italy due to a "detachment letter"?. I'd like to know if this is possible and if the 2 years time could eventually be extended. Also, I would like to understand the procedure that myself and my employer should follow to make this arrangement possible, and how long it will take to set it up. For example, if I wanted to start working remotely from Italy starting next January, would it be enough to request this arrangement one month before the payday? I hope my questions are clear. Kind regards.

Hi,

Your first step would be to write to HMRC for a Liability decision. The address to write to is:

PT Operations North East England
International Caseworker Department
HM Revenue and Customs,
BX9 1AN

Please provide the following information in your letter:

•    your full name
•    your National Insurance Number
•    your date of birth
•    the date you plan on leaving the UK
•    your most recent UK address 
•    your address abroad 
•    the type of work you do
•    your company name and address – UK and abroad if applicable
•    where your contract is held
•    how often you work in the UK – if applicable
•    your normal working pattern (the days, weeks or months you regularly work)

You can request a liability decision as soon as you have all of the relevant information. Please note the current timescale for the area who will process your application is 47 weeks.

Thank you.