A new document shows the CRA registered a lien against a home owned by a person with the same name as someone else who owed taxes.
An official described the blunder to CRA commissioner Andrew Treusch in an August 2014 memo.
"The collection officer did not provide the taxpayer's address to the person who was conducting the property search," the document says.
"When the collection officer obtained the search results, they did not confirm that the address of the property was that of the taxpayer, that the middle name of the property owner was the same as the taxpayer, nor did they check that the name of the other party who was listed as a joint owner was the spouse, or someone else who might be related to the taxpayer."
The Canadian Press obtained a copy of the memo with names and other details blanked out under the Access to Information Act.
The CRA can register a lien against someone's home if they have an outstanding balance on their personal income taxes. The agency also has the power to garnishee wages. These actions are usually only taken once the CRA has exhausted other means of collecting a long-overdue payment.
The document lays the blame for the foul-up on the collection officer.
"Had the collection officer performed the extra steps to confirm that the property was registered to the taxpayer, this error could have been avoided," it says.
The CRA removed the lien once it realized its mistake, the memo says. But liens can hurt someone's credit score and stay with them for years.
The memo writer tried to pass off the mistake as a teachable moment.
"We have identified an opportunity to further clarify and strengthen the messaging to all collection officers of the need for diligence in confirming the identity of the owner of an asset as being the same person as the taxpayer prior to registering an interest in that asset," he told Treusch.
CRA spokeswoman Jennifer McCabe said she could not discuss the details of specific cases.
"The CRA has policies and procedures that govern legal action initiated by collection officers in attempts to collect outstanding tax debts," McCabe wrote in an email.
"When the CRA is made aware of an error, the agency investigates, consults with the impacted parties and takes immediate action to ensure that the situation is rectified.
"As a result of such incidents, policies are reviewed and additional instructions are provided to collection officers to prevent errors from reoccurring."
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