The Fairness at the Pumps Act , which came into effect Aug. 1, 2014, means that businesses stiffing customers by more than half an ounce can be fined, from $250 for each minor offence to $2,000 for a major one.

In what is potentially the most Canadian law ever, bars that advertise a pint of beer or cider must pour the customer 20 fluid ounces, with a half-ounce limit of error. (Head doesn’t count.)

Pub patrons dissatisfied with a venue’s offerings can leave a bad review on Yelp, but they can also get them in trouble in another way — by reporting them to the federal government.

A bartender pours beer at the Mill Street Brew Pub in the Distillery District on Oct. 10, 2008. (Photo: Fred Lum/Globe and Mail via CP)

If you happen to bring a measuring cup along to the pub and determine that you’re being cheated, you can file a complaint with Measurement Canada.

A number of details are needed to submit a complaint, though — info on how you tried to resolve the problem, a photo of the ad or menu showing the quantity you were supposed to get, and a receipt.

Many people may be under the impression that a pint is 16 ounces, but that’s the American measurement. While our southern neighbours use a different system to measure their pints — 16 U.S. fluid ounces equals 473 millilitres as opposed to 455 millilitres in imperial fluid ounces (which we use) — we still get more booze than they do.

But many Canadian bars may be serving you less than you deserve. Two investigations from 2014 — one conducted before the new law came into effect — found that many establishments were withholding beer, with one Vancouver bar even serving 14 ounces.

Fines are rarely handed out: feds

It’s hard to know whether the bars listed in both of those stories have cleaned up their acts.

Innovation, Science and Economic Development Canada, which oversees Measurement Canada, told The Huffington Post Canada in an email that no monetary penalties have been handed out for inaccurate beer measurement so far.

Whenever a business breaks the rules, inspectors opt for a graduated enforcement approach, starting with education instead of slapping a fine on the business right away.

"The vast majority of non-compliances related to beer measurement are resolved in this manner," Hans Parmar from media relations wrote in the email.

So a cheating venue may not be fined right away, but a visit from a government inspector is still intimidating, as is your customers' disapproval. So, note to Canadian bars: don't mess with the beer drinkers of this fine nation.

CORRECTION: A previous version of this story failed to distinguish between imperial and U.S. fluid pints. This version has been corrected.

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