let somebody know

let (one) know

To tell or inform one (of or about something). Be sure to let me know if anything changes between now and then. I let the boss know about the development yesterday.
See also: know, let
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

let somebody ˈknow

tell somebody about something: I don’t know if I can come, but I’ll let you know soon.Let me know how I can help.
See also: know, let, somebody
Farlex Partner Idioms Dictionary © Farlex 2017
See also:
References in periodicals archive ?
"He just left him out there to die," Fitch told the Commercial Appeal, "and I do believe in all my heart that if he had called the police and let somebody know that he shot somebody that my grandson would have been alive today."
It is also important that you let somebody know about your movement.
"If anyone was passing that particular area, has any dashcam footage or just feels that they saw Adam, if they can just get in touch with the police, with missing persons charities, whichever route, just to let somebody know." Karen added: "Any evidence at all, it could be the car's not there as opposed to the car being there, just to give the police a starting point as to when he arrived, because we just don't have any idea at all."
"Let somebody know, somebody that you trust, or if you need to get in touch with one of the helplines.
Let somebody know. We love you and we miss you, and we're waiting here with open arms."
| For all the build-up to the Euros, see Sport and WalesOnline POLICE TIPS FOR FANS TRAVELLING TO FRANCE | Make sure you have your accommodation and travel pre-booked before you get over there | Ensure you let somebody know where you are at all times | Leave plenty of time to go to the games as there will be enhanced safety and security checks at each of the games.
I told my grandson if anyone talks to them about fighting to let somebody know."
Police and Jamie's family are concerned for his welfare and urged him to let somebody know he is safe and well.
Dutton would have been searched for much sooner if he had let somebody know of his itinerary," Miller said.
Make a lunch or coffee date, let somebody know where you're going to be.
Today, as police grew increasingly concerned for Mr Tudge's safety, his wife of 12 years, Jane Tudge, made an emotional appeal for him to let somebody know he safe.
Speak to somebody, let somebody know how you are feeling.
If there's anything at all, no matter how small it is if they let somebody know, the police or through Crimestoppers or whatever, because even the tiniest little thing can be part of a jigsaw that make other things fall into place."
"But we advise them to stay in groups or let somebody know where they are going and catch taxis from official ranks.