Ala. Code § 43-8-250: Contracts Concerning Succession, Etc.; No Presumption of Nonrevocation from Joint or Mutual Wills.

A contract to make a will or devise, or not to revoke a will or devise, or to die intestate, if executed after January 1, 1983, can be established only by:

(1) Provisions of a will stating material provisions of the contract;

(2) An express reference in a will to a contract and extrinsic evidence proving the terms of the contract; or

(3) A writing signed by the decedent evidencing the contract.

The execution of a joint will or mutual wills does not create a presumption of a contract not to revoke the will or wills.