From HMRC in their own words
From February 2016, HMRC will move its bank accounts to Barclays. Most taxpayers paying their bills electronically will be unaffected and do not need to do anything.
Customers who currently pay using Bank Giro or Transcash payslips should consider alternative ways to pay such as electronic payments.
From February 2016 customers making payments from overseas will need to use a new IBAN number when making payments through their bank.
This will be published on GOV.UK prior to February 2016. Any customer group likely to be affected by the changes will be contacted directly.