A Brisbane resident has thrown out his census letter believing it was junk mail because it was addressed to "The Resident".

The Australian Bureau of Statistics has posted out letters, containing crucial online login numbers so households can complete the census.

Anyone who doesn't risks copping a $180 fine for each day they go without completing it.

The man, from the north Brisbane suburb of Zillmere told AAP that he thought he was being "buzzed" by personalised junk mail when he saw it was addressed to "The Resident".

"I just glanced at it and thought it was junk mail and threw it in the recycle bin," he said.

An ABS spokeswoman says it's yet to receive any feedback about people binning letters because they've been mistaken for junk.

She said if anyone has made a mistake they should call the census hotline - which is already struggling with the volume of calls - to get a new one.

"To my knowledge we haven't had any inquiries about people chucking out their letters. People are more worried about receiving them in time for the census because there seems to be a delay in rural areas," the spokeswoman told AAP.

"We were trying to advise everybody that the census is happening and if you do throw it in the bin, it's unfortunate because you won't be able to log on and complete the census."

She advised that anyone calling the census hotline, should do so after 5pm because of long wait times being experienced during office hours.

Census night is Tuesday, August 9.