The Liberal government spent more than $1 million sending postcards to remind people in four provinces to claim the carbon tax rebate.

According to the document tabled in parliament on Monday, the Canadian Revenue Agency sent 7 million cards to households in Ontario, Manitoba, Saskatchewan and New Brunswick during tax season to remind them to claim the “Climate Action Incentive” when filing their taxes. The cards cost taxpayers $1,016,345.74 to print and deliver.

The cards prominently featured the maximum amount of money the taxpayer may have been eligible to claim with the headline: “Have you claimed your Climate Action Incentive payment yet?” and continued with details on the rebate.

According to the document signed by National Revenue Minister Diane Lebouthillier, the CRA did not use 100 per cent recycled paper for the mail outs, as it would have required an alteration to an existing printing contract. They also did not track greenhouse gas estimates on the cards.

The federal government introduced a carbon pricing plan at the pumps for four provinces on April 1 after they refused to introduce their own carbon pricing plans by the deadline.

The rebate -- up to $609 per household, depending on where you live --was meant to offset the increased cost of fuel once the tax went into effect.

The Canada Revenue Agency said the mail outs were part of a “comprehensive marketing campaign” aimed at “ensuring that all Canadians receive the credits and benefits to which they are entitled.”

The CRA added the campaign appears to have worked, as preliminary numbers indicate 97 per cent of eligible families who filed their taxes by May 21 claimed the rebate.