Be in contact with (one) phrase
To share or exchange information, news, ideas, feelings, etc. with someone, especially regularly.
Hardly anyone keeps in contact with friends from their childhood.
Although he moved away, we have still been in contact with each other.
If you have any information about the this child, please get in contact with me by this number.
to be in touch or communicate with somebody, primarily through telephones; to take or grasp somebody physically; to obtain one's reputation.
To wave at a vehicle as a signal for the driver to stop
The origin of this phrase is not clear.