Only in relatively rare circumstances is a deed required to complete a transaction. In a commercial situation the most common use is where a variation or concession is made without the other party giving anything in return. A deed is enforceable regardless of the legal requirements for contracts such as the need for consideration.
Where a deed is necessary, there are special requirements for a company wishing to enter into such an arrangement which may either involve use of the company seal or the signature of two directors or a director and a company secretary.