Which meaning?
The term sometimes refers to a form of mockery in which the mocker exaggerates the other person's characteristics; pretending to take on his or her attitudes, etc., in order to make them look funny. Or it may be used to refer to a ruse where a person is led to believe something is true that is not (usually a fairly unbelievable story) for the purpose of ridicule of the subject.
The phrase is in common usage throughout British society, employed by headline writers in broadsheet gazettes[2] and tabloids[3] as well as colloquially. It is also used in English speaking countries such as Australia.
In colloquial usage, 'taking the piss' is also used to refer to someone or something that makes a claim which is not in line with a recognised agreement e.g. an invoice that is double the quoted price with no explanation for the added charge could be said to 'take the piss', or likewise if something consistently misses a deadline.
The term can also mean to take unfair advantage. For example, if someone has a food buffet and one guest clearly takes more than their expected share. It can also relate to an abuse of trust, such as "You can use my 'phone, but don't take the piss!"
Semicolon, where are you? We miss you!