HM Revenue and Customs has announced a sweeping programme of closures for all its local offices, with the expected loss of thousands of jobs.
Three of Preston's offices will be closed, and the remaining three will be transferred to the Department for Work and Pensions.
The move will affect more than 2,000 employees in Preston.
Blackpool's office will also be transferred to the DWP, and the Blackburn office will close.
It is part of a national programme to close all 170 local tax offices and replace them with regional centres.
Liverpool and Manchester will be the locations for the North West regional offices, which are expected to open by 2018.
Lin Homer, HMRC’s Chief Executive, said: “HMRC has too many expensive, isolated and outdated offices. This makes it difficult for us to collaborate, modernise our ways of working, and make the changes we need to transform our service to customers and clamp down further on the minority who try to cheat the system.
“The new regional centres in Liverpool and Manchester will bring our staff together in more modern and cost-effective buildings in areas with lower rents. They will also make a big contribution to the economy of the North West region providing high-quality, skilled jobs and supporting the Government’s commitment to a national recovery that benefits all parts of the UK.”