LMK

LMK means “let me know.” It asks someone to get back to you with an answer, a decision or an update.

What does LMK mean?

LMK is short for “let me know.” It usually comes at the end of a message that asks a question or makes a plan, and it puts the next move in the other person’s hands: “Free Saturday? Lmk.”

It’s polite and low-pressure, which is why it’s used both with friends and in casual work chats.

How to use LMK

• “Thinking of ordering pizza, lmk if you want any.”
• “Lmk when you land.”
• “Here’s the draft, lmk what you think.”
• “I have an extra ticket for Friday, lmk by tonight?”

LMK vs. HMU

Both ask the other person to get in touch, but they’re used differently. LMK asks for specific information or a decision. HMU (hit me up) is more open-ended: contact me, whenever, about whatever.

Is LMK okay at work?

In chat apps like Slack or Teams, usually yes. In formal emails, spell it out (“please let me know”), especially when writing to clients or people you don’t know well.

Where LMK comes from

LMK grew out of texting and instant messaging as a shortcut for a very common phrase. Its first use isn’t documented.

Related terms

• HMU: hit me up.
• Wyd: what (are) you doing?
• BTW: by the way.
• Idk: I don’t know.

See more terms like this in our texting abbreviations guide.