On the house is an idiom that came into use about 150 years ago. We will examine the meaning of the idiom on the house, where it came from, and some examples of its use in sentences.
On the house means that a drink, meal, or other goods or service is provided at no charge. On the house means that something is free. The idea is that the “house,” meaning the establishment or business, is paying for the goods or service–the charge is on the “house’s” tab. Usually, something will be offered on the house when a customer is celebrating a milestone like a birthday, when a customer is a good patron and the proprietor wants to show his appreciation, or when something goes wrong with the goods or service provided. The expression on the house came into use in the 1880s.
When customers at Afghan Village restaurant can’t afford a meal, our waiters make them an offer they can’t refuse: It’s on the house. (Houston Business Journal)
And, even though Mikayla’s birthday has passed, her mom said a trip to Foxwoods is still in the cards – and it’s on the house. (Fall River Herald News)
If you can eat this gargantuan meal in 20 minutes, it’s on the house. (Brandenton Herald)
Plus, if you know it’s a company policy, surely that ruins the thrill of a barista’s wink that means “it’s on the house”? (The Guardian)