Former Metropolitan Police officer David Carrick has been charged with eight sexual offences against two women.
The 49-year-old faces five counts of indecent assault against one woman.
Hertfordshire Police also charged him with two counts of rape, one count of sexual assault and one count of coercive and controlling behaviour against another woman.
Detective Chief Inspector Iain Moor said it followed “an extensive and complex investigation conducted over a period of several months”.
The Crown Prosecution Service (CPS) said Carrick would appear at Westminster Magistrates’ Court on 17 October.
Lisa Ramsarran, chief prosecutor in Thames and Chiltern, added: “As criminal proceedings against this defendant are active, there should be no reporting, commentary or sharing of information online which could in any way prejudice his right to a fair trial.”