13 Pa.C.S. § 5115

An action to enforce a right or obligation arising under this division must be commenced within one year after the expiration date of the relevant letter of credit or one year after the cause of action accrues, whichever occurs later. A cause of action accrues when the breach occurs, regardless of the aggrieved party's lack of knowledge of the breach, except that, in the event of a fraud or forgery adversely affecting the aggrieved party, a cause of action accrues on the earlier of the date on which the fraud or forgery was discovered by the aggrieved party or the date on which the fraud or forgery could have been discovered by the aggrieved party by the exercise of reasonable diligence.