To say that something is in black and white means that there is written proof of it. It’s an obligation. It’s written in black and white in your contract.
clinch a deal
In a business relationship, if you clinch a deal, you reach agreement on a proposal or offer. Tom’s final argument enabled us to clinch the deal.
a done deal
This expression is used to refer to an agreement or decision which has been reached on a certain matter We’re still considering several proposals, so it’s not a done deal yet.
When an agreement is neither written nor signed, because the two parties trust each other completely, it is called a gentleman’s agreement. It was a gentleman’s agreement. I can’t change my mind now!
a matter of form
If you do something out of politeness, or because it is accepted practice or the usual way of doing something, you do it as a matter of form. I know we’re in agreement, but I need your signature as a matter of form.
sign on the dotted line
If you sign on the dotted line, you formally give your consent to something by signing an official document. I consulted my lawyer before signing on the dotted line.
signed, sealed and delivered
When an agreement, contract or treaty is signed, sealed and delivered, all the legal documents have been signed. It is hoped that the agreement will be signed, sealed and delivered before the end of the week.
A transition that is fair and honest, or an equitable arrangement, is called a square deal. We’ve used the same supplier for years and we always get a square deal.
no strings attached
If something is offered or obtained with no strings attached, it comes without any special conditions or restrictions. I managed to get a loan with no strings attached.
with one voice
Two or more groups or organizations who are in complete agreement are said to speak with one voice. For once the government and the trade unions are speaking with one voice.