Benjamin Hannam, 21, has been suspended from duty in the Metropolitan Police following an investigation by the Metropolitan Police’s Counter Terrorism Command.
Mr Hannam will appear at Westminster Magistrates’ Court in August.
It is alleged that he belonged or professed to belong to the proscribed group between December 2016 and January 2018 and that he falsely represented himself in his application to join the Metropolitan Police in this connection.
He is also charged with other, unrelated but serious offences.
Deputy Superintendant Ella Marriott said: “These are extremely serious charges for anyone to face, and I fully understand and appreciate how deeply concerning it might be for the public, and particularly local communities here in north London, that the charges are against a serving police officer.”
National Action was proscribed as a terrorist organisation in December 2016 following a long campaign by Campaign Against Antisemitism and others. Under section 11 of the Terrorism Act 2000, membership of a proscribed terrorist organisation is a criminal offence.