Short pours are a pet hate of any discerning drinker at bars and pubs and now licensed premises are under the gun as authorities begin a nationwide crackdown.

The National Measurement Institute on Monday said it would begin a secret, one-week blitz to crack down on inaccurate serves of alcohol in licensed premises across Australia including Perth.

NMI legal metrology general manager Bill Loizides said trade measurement laws ensured patrons got what they paid for when buying products like beer and spirits by weight, volume and number.

"Hotels, bars and clubs are on notice and can expect a rigorous but fair approach during the inspections," he said.