The agreement between the UK and the Swiss Confederation taxation ended on 31 December 2016.
HMRC made an agreement with the Swiss tax authorities with a view to ensuring that residents in the UK with funds invested in undisclosed Swiss bank accounts pay tax on those funds in the UK.
HMRC wrote to many UK residents who held Swiss bank accounts. The letter asked you to confirm that you have nothing to disclose or asks that you confirm that you intend to make a disclosure of unpaid taxes to HMRC. If you received one of these letters you would have had to seek advice straight away
If you think you may have unpaid tax in relation to Swiss assets, you should consider making a disclosure to HMRC.
Depending on your circumstances the following options may be available to you: