Beckham, 43, pleaded guilty to the offence in Bromley Magistrates Court on Thursday and additionally received a fine of £750 and was ordered to pay £100 costs and a £75 surcharge fee.
Having already accrued six points on his United Kingdom driving license, the suspension for the ex-midfielder is automatic due to the additional six ordered due to this latest offence.
Beckham was spotted by a member of the public using his mobile phone back in November at the wheel of his vehicle in London's West End.
"Instead of looking straight forward, paying attention to the road, he appeared to be looking at his lap," prosecutor Matthew Spratt told the court.
"[The witness] says that the defendant was operating a handheld device at knee level. At that moment a photograph was taken.
"The defendant was holding the mobile phone in the upright position."
Speaking in Beckham's defence, lawyer Gerrard Tyrell claimed that his client had no memory of infringing the law against using telephones or other electronic devices while driving but would still plead guilty.
"There is no excuse for what took place but his view is as he cannot remember... he's going to plead guilty and that's what he's done," he explained.
It is not the first time that Beckham has faced accusations of committing a traffic offence, though he managed to avoid punishment in the past.
In 2018, the former player was cleared of speeding on a technicality, as the notice informing of the infraction was sent outside of the 14-day notification period set by UK law.
While at Manchester United he was also fined but escaped a ban after the presiding judge accepted his argument that he had broken the speed limit in order to escape paparazzi photographers.