The bank said the order obtained in October, which is known as an unnamed person requirement, was "inordinately broad," The Mail and Globe reported Monday.
The bank also said in a statement that certain "legal conditions" had not been satisfied to allow the court to issue the order on behalf of the Canadian Revenue Agency.
The debate is beginning to resemble the United States versus Swiss Bank UBS tax case, which began with a UBS banker admitting he had helped wealthy U.S. clients hide assets from the IRS, the Toronto newspaper said.
UBS eventually agreed to pay $780 million in fines and release the names of 4,500 clients.
In Canada, the court order was given after "Taxpayer X" told authorities he was advised by an investment adviser to hide $200,000 from tax authorities through a Credit Suisse office in Vancouver, British Columbia.
The Canadian precedent was set in 2008, when an appeals court refused to quash an order for the Web site eBay to turn over the names of sellers thought to be hiding income from the CRA, a law professor said.
"In that case, they were trying to get information on eBay's clients, and the information didn't belong to eBay, and it was stored on servers in the U.S., and the court still said you could get it," said David Duff, an associate dean at the University of British Columbia.
No date has been set for a court hearing on the case, the newspaper said.