Okla. Stat. tit. 10, § 10-7700-308: Proceeding to challenge acknowledgment – Commencement

– Burden of proof.

A. After the period for rescission under Section 7700-307 of

this title has expired, a signatory of an acknowledgment of

paternity may commence a proceeding to challenge the acknowledgment

only:

1. On the basis of duress or material mistake of fact within

two (2) years after the acknowledgment is executed; or

2. On the basis of fraud at any time in accordance with

subsection D of Section 7700-607 of this title.

B. After the period for rescission under Section 7700-307 of

this title has expired, a signatory of a denial of paternity may

commence a proceeding to challenge the denial only:

1. On the basis of fraud, duress or material mistake of fact;

and

2. Within two (2) years after the denial is executed.

C. A party challenging an acknowledgment of paternity or denial

of paternity has the burden of proof, which shall be by clear and

convincing evidence.