The old branch on 124 Deansgate, which first opened over one hundred years ago, will close at 5.30pm today.
The new branch on 12 Oxford Street, which will be run alongside a newsagent, will open tomorrow morning at 9am.
The newsagent will be run by independent retailer Boltonn Ltd on a franchise basis.
The proposal to move the town centre’s main branch promised a bright, modern open-plan layout which would include a complete internal refurbishment, along with a new shop frontage.
The new town centre branch will be located approximately 230 metres away from the old neo-Georgian building on Deansgate.
The new retailer will sell confectionery, tobacco and news alongside the Post Office services which will be available at the new retail unit.
The move has been made because the current branch was deemed unsustainable for the future and the majority of post offices are run as franchises or on an agency basis alongside shops.
Roger Gale, Post Office’s network and sales director, said that the new Bolton branch would help secure the long-term viability of services.
He said: “We are making sure we take the right action to sustain services for years to come.”
The same Post Office services will be available at the new branch with the exception of the specialist biometric enrolment service on behalf of the Home Office.
Opening hours will be extended at the new branch, meaning that Post Office services will be available to customers for an additional 13.5 hours per week.
Post Office services at the new branch will be available from 8am until 6pm Monday to Fridays, 9am until 6pm on Saturdays and 11am until 4pm on Sundays.
A Post Office spokesman said: “The new premises will be completely refurbished with the Post Office in a dedicated area with six serving positions, alongside a retail offer of confectionery and news.
“To ensure good access for all Post Office customers the new branch will include low-level counters, PIN pads, hearing loops and customer seating.
The 16 members of staff currently employed at the town centre branch have had their options discussed with them on an individual basis.
These options include redeployment, voluntary settlement or transfer of employment to the franchisee.
Behind the counters of the old Post Office branch, there is a war memorial located on the wall that is dedicated to colleagues who worked for the organisation when it was known as the General Post Office, which included what is now Royal Mail.
The Post Office is working with Royal Mail to identify an appropriate place to relocate the memorial so that members of the public can continue to pay their respects to those who sacrificed their lives.
A rededication ceremony will take place once a new location has been identified but until then, the memorial will remain in place.
During the consultation to relocate Post Office services, 29 representatives were received and meetings held with the local authority and customers.
Positive feedback included that the new branch was more central, with better access and longer opening hours.
Concerns about the relocation included the size and the impact of town centre events such as street markets.
Bolton Council is looking at the regeneration for some of Deansgate as part of its £1 billion town centre masterplan.
The building in Deansgate is owned by the Jersey-registered Makan Investments Limited and rented to the Royal Mail.
Makan Investments Limited bought the building for £2.15 million in 2006.
However, a spokesman for the council said the Post Office building does not form part of the masterplan.