We will keep you updated

You usually place this at the end of a message. It works perfectly in emails, phone calls, or even texts. You can use I if you are the only one working. Use we if you are representing a whole company or team. It often follows a sentence about a delay or a process. For example, "The team is still reviewing your file." Then, you add the magic phrase to finish. It’s like a polite way to end a conversation.

Use it when you are waiting for a third party. Maybe a boss needs to sign a paper. Maybe a flight is delayed by a storm. It is great for job interviews or apartment applications. If a friend is waiting for your test results, use it then too. It shows that you are reliable and organized. People feel better when they know news is coming. It reduces their anxiety about the unknown.

Do not use this if you already have the information. That feels like you are being lazy or avoidant. Also, avoid it if you know there will be no update. If the project is canceled, just say so. Using it too often without actually sending updates is bad. You will lose people's trust very quickly. It is a promise, so you must keep it! Don't use it for small, instant things like passing the salt.

In many English-speaking cultures, silence is stressful. People prefer a small update over total silence. This phrase became a standard safety net in corporate life. It protects the speaker from being asked "any news?" every five minutes. It establishes a rhythm of communication. It shows respect for the other person's time and feelings. It is the ultimate professional courtesy.

I'll keep you posted is the most common casual version. You use this with friends or close colleagues. I'll keep you in the loop sounds a bit more modern. It implies they are part of a special group. I'll get back to you is more direct and specific. Further updates will follow is very formal, like an official announcement. Use I'll let you know for very simple, everyday plans.