Meaning/Usage: Used to tell someone that you made a mistake

Explanation: This is a very common phrase. It is not as bad as "I blew it" but it also means to make a mistake. However, "I blew it" refers to making a big mistake to lose out on an opportunity, while "I messed up" can be used more freely to indicate any sort of mistake.

"I messed up. I got a ticket for speeding on the highway."
"I messed up, I lost my wallet at the airport."
"He is really upset with me. I messed up."

A. "Why did it take you so long to get here?"
B. "I messed up and got lost."
A. "Really, how did that happen?"
B. "I was not paying attention and took the wrong exit to get here."

Other Common Sentences

"I made a mistake."
"I did the wrong thing."