Orange has apologised to 40 UK call centre staff who were wrongly told their jobs were being outsourced to the Philippines, blaming the scare on "human error".
Union leaders had earlier voiced concern over planned changes to the centre in Darlington, County Durham, saying that staff faced redundancy, lower pay or "unrealistic" relocation half-way around the world.
The company said it was in contact with the 40 employees involved and will be making it clear it was not proactively asking or expecting people to move to Manila.
"The information given out was not done officially and we apologise to those involved. In the case of work transferring locations, the individuals do have the right to request moving with that work, and we have a duty of care to discuss the option.
"We recently proposed some operational changes to our nightshift customer services for the Orange brand. As part of a business process decision, overnight consumer calls will in future be handled by an existing outsource partner in Manila during their daytime hours.
"In accordance with UK employment law, we've completed a collective consultation and are now holding discussions on an individual basis. All 40 of our consumer nightshift team based in Darlington will be offered alternative roles in the UK, or redundancy terms," said a spokesman.
The Communication Workers Union said it was worried about the impact of the move on jobs in the North East.
Union official Kevin Leetion said: "Night shift staff at Orange's contact centre in Darlington are being told they face redundancy, lower pay or an unrealistic relocation half-way around the world.
"They are understandably concerned about their futures, and we are very worried about the long-term employment implications of this shift for jobs in the North East.
"Staff are also disappointed by the lack of consultation from the company on this change so we're asking Orange to put employment issues at the top of their list. Upsetting staff is not good for morale or customer service so treating people well makes good business sense."
Workers had an option of moving from nights to a day shift, but they would lose allowances worth up to £8,000, said the union.