Many people worry about their frequent flier miles, such as how to maximize them and avoiding blackout dates, but something far fewer people think about is what happens to someone's miles after they pass away. Miles and points can both be passed on to surviving relatives or other named beneficiaries upon the owner's death, according to USA Today.

"I have made sure that, in my last will and testament, all my frequent-flier miles and any hotel points go to my wife," Ken Means, a director of engineering in Grand Prairie, Texas, told USA Today. He has over 650,000 airline miles and hotel points.

Those accumulated points and miles can be redeemed for many different travel rewards, such as free flights, complementary hotel stays and other merchandise.

However, not all airlines allow this. Delta, Hawaiian, JetBlue, Southwest and Spirit airlines don't allow passengers to bequeath these particular assets. Choice, Omni, Red Roof and Shilo hotels also don't allow hotel points to be transferred to another owner.

Some companies just don't have an official policy. Virgin America doesn't have "a formal published policy," Abby Lunardini told USA Today. However, they do transfer points to beneficiaries or family members on "a case-by-case basis."

United Airlines doesn't allow transfers, but they have made exceptions after death or divorce, according to spokesman Rahsaan Johnson. They can be transferred at the airline's web site, where users will have to pay $15 per 1,000 miles as well as an additional $30 transaction fee. However, beneficiaries can inherit miles for a flat $150 fee as well.

While the policy on inheriting points and miles varies, only United charges a fee for the transaction.

According to George Hobica, the President of airfarewatchdog.com, if airlines "issue blanket statements" in their frequent-flier rules prohibiting transfer, contacting the company's program by phone may allow for an exception.