shake hands on it

We shake hands on it, Inkling and I. It is strange shaking hands with an invisible creature.

“Nat, I’m sorry about yesterday. Will you shake hands on it?”

Do the deal with Chelsea now, shake hands on it and fill in the paperwork in January.

“I do delegate,” he said, later adding, “If you tell me you're going to do something, we shake hands on it. I trust you. It's served me well.”

Mr Balls got the chancellor to shake hands on it on the Andrew Marr programme after making the surprise offer.