The restructure reflects a need to cut costs due to expressions of interest in the business.
Administrators are continuing discussions with other parties to dispose of Phones 4U stores and the transfer of employees.
PwC partner and joint administrator Rob Hunt said: “It is with great sadness and regret that we have today made the difficult decision to make 628 head office and telesales staff redundant.
“Our thoughts are with those employees at this difficult time. We will make every effort to help the affected staff, working with the Phones 4u HR team over the coming days to support employees.”
The high-street retailer closed its doors on Monday after EE announced it would not be working with Phones 4u in the future. This followed decisions by the other major mobile phone networks to sever ties.
Dixons Carphone offered jobs to 800 Phones 4U staff on Wednesday. The retailer has 5,596 staff in total.
