Filer
A filer is a person whose name appears on the Active Taxpayers List, meaning they filed their income tax return for the relevant year on time.
Filing alone is not enough if it was late. The status is checked on the date of the transaction, so a return filed the day before a property transfer does not help, because the list only updates weekly.
Related terms
ATL
The ATL is the FBR's weekly published list of taxpayers who have filed their return on time, and being on it is what qualifies you for the lower withholding tax rates.
Non-filer
A non-filer is a person not on the Active Taxpayers List, who therefore pays substantially higher withholding tax on banking, vehicles, dividends and property.
Late filer
A late filer is someone who filed their return after the due date, and a separate middle rate of tax applies to them on property transactions.