Do you have unused Air Miles? Depending on how long you've had them, you may want to use them before you lose them.

In 2011, Air Miles announced an expiry policy, which takes effect Dec. 31 of this year when miles older than five years begin to expire on a quarterly basis.

That came as news to Halifax resident Noreen Delaney, who uses her Air Miles card at every opportunity. She had heard nothing about the expiry until informed by CBC News.

"You'd think they would send you a letter or a phone call," she said, adding: "I never heard anything from them."

Delaney is one of 11 million active Air Miles collectors in Canada, according to Air Miles spokeswoman Kahina Haffad, who said some collectors are "still not using the miles they collected decades ago."

Delaney wonders why the miles are expiring at all.

"We believe five years is very reasonable to expect someone to use miles and get a reward that betters the way they live their lives every day," Haffad said in an email to CBC News.

Scour the website

She said miles posted to collector accounts are date-stamped and, if not used, removed from accounts five years later, on the last day of that quarter.

Collectors who are unaware of the expiry policy will not see any information about it on the main page of the Air Miles website. You will have to search for it. Information can be found under Browse FAQs.

Haffad said collectors can go online and request their personalized expiry information, allowing them to use or cash in their miles before they disappear.

But expiry policies have not gone over well in some other instances.

A class action lawsuit was launched when Aeroplan made a similar announcement several years ago, saying points unredeemed seven years after they were collected would expire. The company cancelled the plan in 2013 following a public outcry.

Shoppers Optimum

Aeroplan collectors, however, can still lose their points. If the collector doesn't use their card or points at least once in a 12-month period, the accumulated points will be wiped out.

Loyalty cards are popular in Canada. A 2013 survey by Colloquy, a loyalty market research firm, showed the average Canadian household is a member of more than eight loyalty programs.

A survey the same year by Abacus Data showed Air Miles as the No. 1 rewards plan in Canada, followed by Shoppers Optimum.

Shoppers does list an expiry date of March 31, 2017, for redeeming its Optimum points, but the company says it doesn't plan to enforce that expiry date.

Spokeswoman Tammy Smitham says there has always been a termination date in their terms and conditions, but every year they review the date and push it forward.

"Over time, we have amended that date to continue the program," she said.

"There are no immediate plans to change or end the program, and therefore customers do not need to use or redeem their points."