A spokesman for Munich's customs office said the teenage singer has until midnight to contact them, otherwise capuchin monkey Mally will be transferred to a permanent home at a zoo or animal park elsewhere in Germany.
"If no further documents arrive then the seizure order comes into effect and the animal becomes the property of the German state," customs spokesman Thomas Meister told The Associated Press.
Mally was seized by German customs March 28 when Bieber failed to produce required vaccination and import papers after landing in Munich while on tour.
The now 20-week-old animal was quarantined and cared for at Munich's animal shelter, where manager Karl Heinz Joachim said Mally had fared well and gained weight.
The shelter has criticized Bieber for keeping such a young monkey as a pet, saying it shouldn't have been taken away from its mother until it was a year old. Experts say capuchin monkeys also need to be kept in groups as they are very sociable animals.
"The best thing would be not to buy one at all, but if you do, buy five," said Joachim.
He said emails from Bieber's management to the animal shelter indicated the singer doesn't want the monkey anymore, but that the final decision would have to be made by German authorities.
"Our contact is the person that the monkey belongs to," said Meister, the customs office spokesman. "We've had contact with lots of people but none of them was an authorized representative."
Meister said the cost of care, food and vet visits at the Munich shelter amounted to several thousand euros (dollars).
"You can bet we are going to ask for that money back," he said.