"agreed beforehand" is a correct and usable phrase in written English.
It means that something has been decided or arranged in advance. Example: The terms of the contract were agreed beforehand, ensuring that both parties were satisfied with the agreement.
A spokesman for McDonnell said the general thrust of the speech had been agreed beforehand.
The timing was agreed beforehand with Gary to take place after the international break so as to minimise disruption to the Valencia team.
But a spokesman said that while the mortgage was created after he became a Minister, the loan had been agreed beforehand.
This is the reference weapon, which both players have agreed beforehand is genuine perhaps it was removed at random from a missile silo in the inspector's presence.
The Lib Dems are prepared to sign up to the mass opt-out but only if the Conservatives agreed beforehand to provide the list of measures that Britain would immediately ask permission to opt back into.
Johnson used the summit to table a plan, agreed beforehand in bilateral talks with the US secretary of state, Rex Tillerson, that targeted sanctions could be applied to senior military figures deemed responsible for last week's devastating chemical attack.
Members of a group agree beforehand on whether to follow this procedure.
In this type of arbitration, parties attempt to reduce the risk of extreme decisions by agreeing beforehand on the upper and lower limits of any monetary award.
All of the money could be spent on living expenses or a portion earmarked books, but it's best to agree beforehand.
To avoid a repeat of such trauma, he said, the island decided to choose mayors by consensus, finding someone on whom everyone could agree beforehand.
For tenants sharing a property with friends, it can help to agree beforehand to be jointly responsible for the rent, instead of singly responsible which may put some landlords off.
