Rule 5.275. Burden of Proof in Will Contests

(a) In all proceedings contesting the validity of a will, the burden shall be upon the proponent of the will to establish prima facie its formal execution and attestation. Thereafter, the contestant shall have the burden of establishing the grounds on which the probate of the will is opposed or revocation sought.

(b) In any transaction or event to which the presumption of undue influence applies, the presumption shifts the burden of proof under sections 90.301–90.304, Florida Statutes.