BT is to shut offices in more than 270 locations across the UK as the telecoms company seeks to cut £1.5bn in costs.

The company is to cut the number of locations across the UK where it has offices to 30, a reduction of more than 90% in its UK property footprint.

It has announced that the first eight locations for its UK workforce, which is being whittled down to about 75,000, will be London, Manchester, Cardiff, Edinburgh, Belfast, Bristol, Ipswich and Birmingham. BT says these are “key locations” for the group to maintain a presence.

BT said that choosing sites in all four home nations is a “clear signal that BT is committed to the whole of the UK”. Under the workplace consolidation programme, which is expected to be completed by 2023, some existing BT buildings will be refurbished while others will be new offices.

The move “is about bringing our people together in brilliant spaces, and transforming the way we work”, said Philip Jansen, BT’s chief executive. “We have dedicated teams working on identifying the right buildings to move into, or which ones to redesign for the future. BT will be housed in inspiring, future-fit offices that are better for our people, better for our business, and better for our customers. And we’re going to be in constant dialogue with all our colleagues every step of the way to get their feedback, so we can ensure our buildings truly inspire them.”

Prospect, one of the largest unions representing BT workers, said the closure of so many offices needed to be handled carefully as it would have a serious impact on staff.

“Moving from an estate of over 300 locations to around 30 by 2023 poses a huge logistical challenge for all concerned,” said Noel McClean, Prospect’s national secretary. “For example, closing each existing building will require a period of consultation and considerable support for affected staff, from both the company and the union. Therefore, it is imperative that Prospect maintain a close and regular dialogue with the company as the programme unfolds.”

Last May, BT announced plans to cut 13,000 jobs over three years, and move out of its central London headquarters after almost 150 years, to cut £1.5bn in costs after a torrid 18 months. In May, BT’s share price hit its lowest level since 2011.

BT is closing in on a £200m-plus deal to sell its London headquarters in St Paul’s, where it has been since 1874 when the group was known as the General Post Office, with the preferred option for a new London base in a development in nearby Aldgate. BT said the property consolidation plan will mean it retains its network of telephone exchanges across the UK.

In 2001, BT moved to sell the bulk of its property estate, about 6,700 offices and telephone exchanges, to raise £2.4bn to reduce a £30bn debt mountain. Under the deal, BT agreed to lease back the property for 30 years with hefty annual rent payments.

Last month, Jansen, who took over from Gavin Patterson in February, unveiled an initiative to give employees £50m in shares annually as part of a scheme to boost morale and rebuild the telecoms group’s image.

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Jansen’s move followed a tough couple of years for BT, which has included an Italian accounting scandal and a profit warning that stripped billions off its market value.

About two-thirds of the job cuts announced in May last year will fall on its UK workforce of about 83,000, with the remainder coming from the 23,000 staff it employs internationally. BT has already made thousands of the cuts, incurring £386m in restructuring charges in the year to the end of March, a 60% annual increase, “primarily relating to leaver costs”.

BT’s unions have raised concerns that the job cuts appear to be an “out with the old, in with the new” strategy targeting the company’s long-serving staff.