A 15-year-old and 16-year-old had been on trial at Shrewsbury Crown Court for their part in a raid on the store at the Forge Retail Park.
They had both admitted stealing from the store but denied robbery, that is, theft using violence or the treat of violence.
But on Tuesday a jury returned its verdict that both were guilty of robbery.
The younger boy was accompanied by a Romanian interpreter at court, while the 16-year-old was not present.
Another youth and two other men who were involved had previously admitted robbery but could not be sentenced until the trial of the 15-year-old and 16-year-old had finished. At the time of writing a sentencing date had still not been set.
Prosecutor Steven Bailey told jurors the gang of five, none of whom lived in the area, travelled to Telford in an Audi A3 on November 10 last year with the intention of robbing the store.
They also heard evidence from the employees who were in the store when a gang of three teenagers and a man, David Stefan, entered the shop on November 10 last year.
The driver, Maxim Voicu, stayed in the vehicle, which was deliberately parked out of view of CCTV cameras, while the three teenagers and David Stefan entered the shop at 10.17am.
'You move, I stab you'
Carphone Warehouse manager Christopher Watkins was inside the store at the time, along with staff member Cerys Lowe and several customers.
Giving evidence earlier in the trial, Mr Watkins said one of the alleged robbers shouted “you move, I stab you,” while the other three ran around the shop shouting and taking things from display stands.
An iPhone and two Samsung tablets were stolen in the raid along with a number of phone cases.
Shop worker Cerys Lowe said that when she attempted to press the store’s panic button, she was told "you move, I stab you".
The 15-year-old said under cross-examination by Mr Bailey that he did not hear the comment being made.