Sec. 2. What constitutes certainty as to sum. The sum payable is a sum certain within the meaning of this Act, although it is to be paid:

(a) with interest; or
(b) by stated installments; or
(c) by stated installments, with a provision that, upon default in payment of any installment or of interest, the whole shall become due; or
(d) with exchange, whether at a fixed rate or at the current rate; or
(e) with costs of collection or an attorney's fee, in case payment shall not be made at maturity.

WITH INTEREST

> The fact that the sum payable is to be paid with interest doesn’t render the sum uncertain
> Amount can easily be computed
> When interest is stipulated but not specified, the legal interest shall be used
> Where there is no stipulation, the legal rate shall be paid when the debtor incurs delay
> Interest due shall earn legal interest from the time it is judicially demaned, although the instrument may be silent upon this point

ESCALATION AND DEESCALATION CLAUSE—FORMER IS VALID IF ACCOMPANIED BY THE LATTER

> Parties may stipulate that the rate of interest agreed upon be increased in the event that the applicable maximum rate of interest is increased by law.

> Deescalation clause—stipulation in the agreement that the rate of interest agreed upon shall be reduced if the maximum rate of interest is decreased by law.

BY STATED INSTALLMENTS

1. It must be stated
2. The maturity of each installment must be fixed or determinable—required in order to comply with the requisite that the instrument, if not payable on demand, must be payable on a fixed or eterminable future time

BY STATED INSTALLMENTS, WITH ACCELERATION CLAUSE

> Acceleration clause—“upon default in the payment of any installment, the whole sum payable shall become due”
> It hastens the payment of the whole note

WITH EXCHANGE

> While the rate of exchange is not always the same and while it is technically true that the resort must be had to extrinsic evidence to ascertain what it is, yet the current rate of exchange between two places at a particular date is a matter of common commercial knowledge, or at least easily ascertained by anyone so that the parties can always, without difficulty, ascertain the exact amount necessary to discharge the paper
> Applies only to instruments drawn in one country and payable in another

EXCHANGE

> Difference in value of the same amount of money in different countries
> Current rate or fixed rate

WITH COSTS AND ATTORNEY’S FEES

> An instrument may thus stipulate that costs of collection and attorney’s fees shall be paid by the debtor in addition to the principal in case the instrument shall not be paid in maturity

> Although the stipulation will make the sum after maturity uncertain, it will not affect the certainty of the sum payable at maturity and therefore, will not affect the negotiability of the instrument in which it is stipulated

What constitutes certainty as to sum