Umair Hussain, 24, was charged on Thursday with having information about a possible terrorist act and not disclosing it. He will appear before a court on Friday.
The decision came a day after Hussain, who was arrested on August 10, had his custody extended by 24 hours for further questioning.
The decision brought to 12 the number of people that have been charged in the alleged plot to blow up as many as 10 passenger jets using liquid explosives.
Eight suspects appeared in court this week charged with conspiracy to murder and preparing to commit acts of terrorism.
Three others, including the mother of an eight-month-old baby, were charged with lesser offences, including failing to disclose information.
On Wednesday, British police were given another week to question eight remaining suspects in the plot.
Under British anti-terrorism law, detectives can seek a judge's permission to hold suspects for up to 28 days before they must be charged or released.
Five people have been released since the alleged plot was revealed two weeks ago.
Charity funds frozen
Britain's charity regulator has frozen the bank accounts of an aid organisation while it investigates alleged links to the foiled plot.
The Charity Commission said it had launched a formal inquiry into Crescent Relief, which raised funds for victims of last year's Pakistan earthquake.
British media outlets have reported that Crescent Relief was founded in 2000 by Abdul Rauf, whose son Rashid Rauf is being held in Pakistan over his alleged key role in the jet liner plot.
Media reports have suggested that funds from the charity may have been used to support the planned attacks.
Kenneth Dibble, the commission's director of legal and charity services, said: "We are working with law enforcement agencies to get to the bottom of allegations of possible terrorist abuse of Crescent Relief funds.
"The allegations made are very serious, and we are taking this action to protect the charity's funds while the investigation is under way."
The Home Office declined to say on Thursday whether it had requested Rashid Rauf's extradition from Pakistan.