British Foreign Secretary James Cleverly gestures as he speaks during a news conference on Friday, March 17, 2023. AP
The government said it was slapping sanctions on five board directors of a foundation which manages the IRGC's domestic investments, as well as two provincial commanders of the state security service.
It follows a flurry of other sanctions against Iranian officials by London, the European Union and the United States in recent months over Tehran's bloody crackdown on protesters.
"Today we are taking action on the senior leaders within the IRGC who are responsible for funnelling money into the regime's brutal repression," said UK Foreign Secretary James Cleverly.
"Together with our partners around the world, we will continue to stand with the Iranian people as they call for fundamental change in Iran."
The UK has imposed dozens of asset freezes and UK travel bans since the start of the year on Iranian individuals and organisations, including leading IRGC commanders and Tehran's prosecutor general.
The last set of sanctions in January followed Iran announcing that it had executed British-Iranian dual citizen Alireza Akbari for spying for the UK, prompting widespread Western outrage.
Demonstrations have swept Iran since the September 16 death in custody of Iranian Kurdish woman Mahsa Amini, 22, after her arrest for allegedly failing to adhere to the Islamic republic's strict dress rules.
Iran has since arrested at least thousands of people in the wave of protests, according to the United Nations and rights groups.