BT has called for staff to return to its offices for three days a week, claiming it is fundamental to the success of the telecoms business.
Philip Jansen, chief executive, said the new strategy of "three together, two wherever" was the smart way of working.
Staff who refuse to follow the guidance face disciplinary action, according to the story in tech news website The Register.
BT’s missive is the latest sign that doubt is growing among large employers about the benefits of permanent working from home, a phenomenon that took off during the Covid lockdowns.
In an email reported by The Register Jansen said: "We believe in being together. That means most of our office-based colleagues coming together for at least three days a week in the workplace, or with customers.
"Working remotely, we’ve lost that deep connection we only get from being together – with each other or with our customers – more often: the spontaneous conversations, the creative work, and the building of deep human relationships that inspire amazing things for our customers.
"I know this won’t suit everybody’s individual preference, but the whole of the executive team believes it is fundamental to the success of our business."
BT’s directive comes as more staff this week threatened to walk out over pay.
Four hundred 999 emergency call handlers could strike on four days next month, the CWU announced.
These call handlers will be part of 40,000 BT Group workers likely to take part in the strike over pay on 6, 10, 20 and 24 October, said the union.
Staff were granted a £1,500 pay rise in April, an average increase of 5%, but CWU argues this is a “real terms pay cut” due to the current high rate of inflation of over 10%.
The union has noted that BT made a £1.3bn profit tax in the past year and that boss Philip Jansen received a 32% pay rise while “many workers who made that profit rely on food banks and don’t know how they will pay their bills”.
Shares in BT dropped 3% to 130.5p