Debbie Jennings was last seen in Ross on Wye.
Police think a missing woman from Hereford could be in Portsmouth.
29 year old Debbie Jennings who is described as 'extremely vulnerable' was last seen at Ross On Wye bus station on Tuesday.
She was with two people who she had previously lived with, one of whom is not meant to have any contact with her and has bail conditions to stay away from her.
Detective Inspector Martyn Barnes from Hereford CID said: "We consider Debbie to be extremely vulnerable and we need to know that she is safe and well.
"We know Debbie was in Ross On Wye bus station on Tuesday, 10 July, with two people who she has previously lived with: Luke Wilson, aged 46 and his partner Ailsa Wilson, aged 33.
"All three boarded a bus at 9.30am and are now thought to be in the Portsmouth area. Mr Wilson is not meant to have any contact with Debbie and has bail conditions to stay away from her. We are also keen to speak to Ms Wilson about her involvement with this incident.
"I would urge anyone who has seen Debbie or The Wilsons to call us on 0300 333 3000 or Hampshire police on 101.
"If Debbie sees or hears this appeal, please contact us on the numbers above or go into the nearest police station so that we know that you are safe and well.”
The image released of Debbie Jennings was taken around two years ago and she is now described as being slimmer than in that photograph. When Debbie was last seen, she was wearing grey leggings, grey sandals and a thick, black, fleecy jumper. Photographs of Luke and Ailsa Wilson are also issued with this appeal.