Facebook has said it believes there are now more than 83 million illegitimate accounts on the social network.
In company filings published this week, it said 8.7% of its 955 million active accounts broke its rules.
Duplicate profiles – belonging to already registered users – made up 4.8% of its membership figure.
User-misclassified accounts amounted to 2.4% – including personal profiles for businesses or pets – while 1.5% of users were described as “undesirable”.
The estimate comes at a time of growing concern about the effectiveness of marketing on the platform.
Facebook defined duplicates as “an account that a user maintains in addition to his or her principal account.”
It said profiles were “user-misclassified” if “users have created personal profiles for a business, organisation, or non-human entity such as a pet”.
It added that “undesirable” accounts included those using fake names which were “intended to be used for purposes that violate our terms of service, such as spamming”.