"Don't worry about the check"

ITSONME

Think of what you might say when covering a bill for someone else, often heard in casual dining or among friends. The phrase is a common three-word reply that starts with "It's."

This clue plays on the phrase "it's on me," which means someone else is covering the cost—like when you're treating a friend to a meal. The word "check" hints at a bill, so "don't worry about the check" suggests the speaker is paying. The answer, "ITSONME," is a casual way to say exactly that, dropping the apostrophe for crossword-style brevity.