HM Revenue & Customs is to close all 170 of its offices as it seeks to move to a model of 13 regional hubs.
The Telegraph reports the move will put thousands of the Revenue’s 56,000 staff at risk of redundancy, although a spokesman declined to comment.
The changes come after HMRC chief executive Lin Homer told MPs that the service was looking to move more services online.
Homer told the Treasury committee on Tuesday that HMRC was “very apologetic” for failing to answer as many as half of calls received from taxpayers between April and July.
HMRC is not a ring-fenced department, and will be subject to Chancellor George Osborne’s spending review set to be announced on 25 November.
The first new regional centre will open in 2016/17, with others following between 2017 and 2021.
HMRC expects the majority of its staff will be able to move to a regional centre, and is phasing the moves over ten years in order to minimise redundancies.
The changes are expected to generate £100m of estate savings by 2025.
The regional centres will be in Newcastle, Manchester, Liverpool, Leeds, Nottingham, Birmingham, Cardiff, Belfast, Glasgow, Edinburgh, Bristol, Stratford and Croydon.
The tax collector will additionally maintain four specialist sites for tasks that cannot be done elsewhere, where HMRC needs to work with its IT suppliers or other Government agencies or departments. These will be in Telford, Worthing, Dover and at the Scottish Crime Campus in Gartcosh.
Existing offices will be released over time, with some 137 offices expected to be closed by 2027.