Pull out a contract that you happen to have handy, or locate a contract online (for example, a contract to lease an apartment or car). You will draft a clause that you can insert into the contract that requires writing for modification.In an introductory paragraph, tell us the purpose of the contract (lease a car or apartment, purchase a sofa...). In the next paragraph, you will have your clause that requires parties to the contract to make modifications to the terms of the agreement in writing.

I will be using a lease contract