Gaps in NI contributions due to working in Switzerland for 4 years

Dear HMRC Team, I have gaps in NI contributions, as I worked in Switzerland from April 2012 until February 2016. Prior to that, I was working in the UK from June 2011 to March 2012, and paid NI (although not for the full year). Before that I was living outside of Europe. I have a few questions: 1. I worked full time in a professional role in Switzerland for a Swiss company. Would any of my tax payments qualify for National Insurance Contributions in the UK? In other words, is it possible to transfer any tax payments made in Switzerland from 2012-2016 to my UK National Insurance? 2. If the above is not possible, how do I estimate the amount of voluntary NI I can make? 3. How can I calculate the effect on my state pension (i.e. increase in value) if I were to make the voluntary contributions? Many thanks You have: 8 years of full contributions 25 years to contribute before 5 April 2048 5 years when you did not contribute enough 2023 to 2024Your record for this year is not available yet 2015 to 2016Year is not fullView 2015 to 2016details 2014 to 2015Year is not fullView 2014 to 2015details 2013 to 2014Year is not fullView 2013 to 2014details 2012 to 2013Year is not fullView 2012 to 2013details 2010 to 2011Year is not fullView 2010 to 2011details

Hi,
We are unable to advise you on any payments of tax, you would need to contact the tax office for information surrounding tax paid in the UK or another country.
Their contact number is 0300 200 3300, their lines are open from 8am to 6pm, Monday to Friday. 
We can confirm that National Insurance contributions paid in Switzerland cannot be transferred to your UK National Insurance records.
If you want to enquire about paying voluntary National Insurance contributions, you would need to contact HMRC and provide your National Insurance number so we can look into your personal records.
HMRC will be able to tell you if there are any years where you can pay voluntary National Insurance contributions, how much they would be and how to pay.
However HMRC cannot confirm if paying voluntary National Insurance contributions for particulars years, will increase your pension or not.
You will need to contact the Department for Work and Pensions to find this out before sending any payments to HMRC.
Further information can be found here:
Voluntary National Insurance: Gaps in your National Insurance record.
Thank you.