Okla. Stat. tit. 12A, § 12A-4-406

Signature or Alteration.

CUSTOMER'S DUTY TO DISCOVER AND REPORT

UNAUTHORIZED SIGNATURE OR ALTERATION

(a) A bank that sends or makes available to a customer a

statement of account showing payment of items for the account shall

either return or make available to the customer the items paid or

provide information in the statement of account sufficient to allow

the customer reasonably to identify the items paid. The statement

of account provides sufficient information if the item is described

by item number, amount, and date of payment.

(b) If the items are not returned to the customer, the person

retaining the items shall either retain the items or, if the items

are destroyed, maintain the capacity to furnish legible copies of

the items until the expiration of seven (7) years after receipt of

the items. A customer may request an item from the bank that paid

the item, and that bank must provide in a reasonable time either the

item or, if the item has been destroyed or is not otherwise

obtainable, a legible copy of the item.

(c) If a bank sends or makes available a statement of account

or items pursuant to subsection (a) of this section, the customer

must exercise reasonable promptness in examining the statement or

the items to determine whether any payment was not authorized

because of an alteration of an item or because a purported signature

by or on behalf of the customer was not authorized. If, based on

the statement or items provided, the customer should reasonably have

Oklahoma Statutes - Title 12A. Uniform Commercial Code Page 351

discovered the unauthorized payment, the customer must promptly

notify the bank of the relevant facts.

(d) If the bank proves that the customer failed, with respect

to an item, to comply with the duties imposed on the customer by

subsection (c) of this section, the customer is precluded from

asserting against the bank:

(1) The customer's unauthorized signature or any

alteration on the item, if the bank also proves that

it suffered a loss by reason of the failure; and

(2) The customer's unauthorized signature or alteration by

the same wrongdoer on any other item paid in good

faith by the bank if the payment was made before the

bank received notice from the customer of the

unauthorized signature or alteration and after the

customer had been afforded a reasonable period of

time, not exceeding thirty (30) days, in which to

examine the item or statement of account and notify

the bank.

(e) If subsection (d) of this section applies and the customer

proves that the bank failed to exercise ordinary care in paying the

item and that the failure substantially contributed to loss, the

loss is allocated between the customer precluded and the bank

asserting the preclusion according to the extent to which the

failure of the customer to comply with subsection (c) of this

section and the failure of the bank to exercise ordinary care

contributed to the loss. If the customer proves that the bank did

not pay the item in good faith, the preclusion under subsection (d)

of this section does not apply.

(f) Without regard to care or lack of care of either the

customer or the bank, a customer who does not within one (1) year

after the statement or items are made available to the customer

(subsection (a) of this section) discover and report the customer's

unauthorized signature on or any alteration on the item is precluded

from asserting against the bank the unauthorized signature or

alteration. If there is a preclusion under this subsection, the

payor bank may not recover for breach of warranty under Section 4-

208 of this title with respect to the unauthorized signature or

alteration to which the preclusion applies.