[sign] on the dotted line

to sign a document to show that one has agreed to do or buy something

The idiom "sign on the dotted line" originated from the practice of signing legal or official documents. In the past, contracts and agreements were often written on paper with a dotted line indicating where the signature should be placed. The phrase emphasizes the finality and commitment associated with signing an important document. It implies that once a person signs on the dotted line, they are legally bound to the terms and conditions outlined in the agreement.

The entrepreneur was excited about the business deal and eagerly signed on the dotted line, officially sealing the partnership.
The athlete carefully reviewed the sponsorship contract before confidently signing on the dotted line, securing their endorsement agreement.
The homebuyer carefully read through the mortgage agreement and sought legal advice before signing on the dotted line.
After negotiating the terms of the employment contract, the candidate was ready to sign on the dotted line and accept the job offer.
The artist was overjoyed when the gallery offered them a representation agreement, and they wasted no time in signing on the dotted line.