Facebook has begun to implement stricter rules on political advertising in the UK.
The new rules should come into force on November 7, but they were postponed when journalists and researchers discovered shortcomings in the new system.
Anyone who places political ads on Facebook must now verify their identity and location and prove who paid that ad.
Changes were made after the Cambridge Analytica scandal.
The new rules have implications for political alerts regarding candidates, elections, referenda and political reasons.
People who buy ads must provide their identity by sending an ID, which will be verified by a third party.
They also have to show that they have an address in the United Kingdom that corresponds to the mail sent by mail.
Political notices will also be held in the public register for several years.
"Applying these ads will never be perfect, but we will continue to improve our systems and technology to prevent abuse," said the company's announcement.
The new rules were postponed after the Business Insider website could purchase an ad that was "paid by Cambridge Analytica."