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".
Source: BBC News
