She has been banned from driving for three months after admitting driving while disqualified and without insurance.
Price, 40, was also fined £1,100 after pleading guilty to driving on the A24 near her home in West Sussex on 25 July when she mistakenly thought a previous ban had ended.
She had driven from the short stay car park at Gatwick Airport to Dial Post, a hamlet near Horsham, after travelling by train into London to take her son to a medical appointment.
A newspaper called her to let her know she had broken her ban, which was then confirmed by the police.
The former model had been banned from driving for six months in February last year, but her lawyer Paul Macauley told the court she had thought the ban was in place from a hearing in January.
Her working out meant the ban would have finished in early July, before she got back behind the wheel.
She had not contacted the DVLA about reinstating her licence because she was "not the best" at paperwork, Mr Macauley told magistrates.
Price arrived at court in Crawley flanked by two bodyguards and advisers this morning. She removed her Cossack-style fur hat before enterring the courtroom.