What is the Four Corners Rule?
The “Four Corners Rule” states that if the language is not found within the written words of the contract, then outside evidence will not be considered. This includes any oral agreement you’ve made.
How Does this Work?
So, for example, you’ve agreed to buy widgets from a manufacturer. Your contract states that you will buy 100 widgets for $100, and the company must deliver those widgets to you within 30 days. Before the 30 days is over, however, you find widgets for $80. You call the manufacturer to complain, or renegotiate, and the manufacturer verbally agrees to lower the price to $80. Widgets delivered, you pay $80, and then you get sued for the remainder. Your phone conversation will not change a written contract. It can change an oral agreement, but not a written one. If it is not written within the four corners of the contract, you lose.
Get it in Writing!!
Any renegotiation of any of the terms of a written contract must be in writing.