OTTAWA - Snowbirds beware: The federal government will use its planned border exit-tracking system to avoid paying hundreds of millions of dollars in social benefits now going to people who shouldn't receive them due to absences from Canada.

Newly obtained memos say the Canada Revenue Agency and Employment and Social Development Canada expect to save between about $194 million and $319 million over five years once the long-anticipated system is fully in place.

Federal officials have been working quietly to satisfy privacy commissioner Daniel Therrien's office that personal information will be properly collected, used and disclosed under the program.

Under the 2011 perimeter security pact, Canada and the United States agreed to set up co-ordinated systems to track entry and exit information from travellers.

For the moment, the tracking system involves exchanging entry information collected from people at the land border -- so that data on entry to one country serves as a record of exit from the other.

The first two phases of the program have been limited to foreign nationals and permanent residents of Canada and the United States, but not citizens of either country.