Okla. Stat. tit. 15, § 15-325: When promise deemed original

A promise to answer for the obligation of another, in any of the

following cases, is deemed an original obligation of the promisor,

and need not be in writing:

1. Where the promise is made by one who has received property

of another upon an undertaking to apply it pursuant to such promise;

or by one who has received a discharge from an obligation in whole

or in part, in consideration of such promise.

2. Where the creditor parts with value, or enters into an

obligation, in consideration of the obligation in respect to which

the promise is made, in terms or under circumstances such as to

render the party making the promise the principal debtor, and the

person in whose behalf it is made his surety.

3. Where the promise, being for an antecedent obligation of

another, is made upon the consideration that the party receiving it

cancels the antecedent obligation, accepting the new promise as a

substitute therefor; or upon the consideration that the party

receiving it releases the property of another from a levy or his

person from imprisonment under an execution on a judgment obtained

upon the antecedent obligation; or upon a consideration beneficial

to the promisor, whether moving from either party to the antecedent

obligation, or from another person.

4. Where a factor undertakes, for a commission, to sell

merchandise and guaranty the sale.

5. Where the holder of an instrument for the payment of money,

upon which a third person is or may become liable to him, transfers

it in payment of a precedent debt of his, or for a new

consideration, and in connection with such transfer enters into a

promise respecting such instrument.