Is LMK a formal or informal term?

Imk Meaning Text is “Let Me Know,” LMK is a informal term used in texting and chatting or social media. People use LMK to ask someone to share certain information or updates in the casual manner. For instance, while planning a get-together, you may tell the person to “LMK if you can come!” LMK is inappropriate in formal situations, such as business emails or professional conversations. In such cases, it is better to say something like “Please inform me” or “Kindly update me.” In this way, you will maintain a professional tone while still requesting information.