Stephen Webster sold the phones on or gave them to friends and family as presents, Snaresbrook crown court heard.
Webster's job involved receiving invoices, checking the goods, and then signing the invoice before passing it to his line manager for a counter signature.
On one occasion when his boss was not around Webster signed an invoice on her behalf and it went through without question. This gave him the idea for the deception,and he ordered large quantities from mobile phone shops claiming he was acting on the council's behalf.
The council is still in dispute with one mobile phone shop over£10,000.