Liability For Interest Even Without Agreement
Is a person liable for interest even if there is no agreement? No as a rule, because no interest shall be due unless it has been expressly stipulated in writing. (Art. 1956, NCC).
Be that as it may, while there can be no stipulated interest, there can be legal interest pursuant to Article 2209 of the Civil Code. It is well-settled:
When the obligation is breached, and it consists in the payment of a sum of money, i.e., a loan or forbearance of money, the interest due should be that which may have been stipulated in writing. Furthermore, the interest due shall itself earn legal interest from the time it is judicially demanded. In the absence of stipulation, the rate of interest shall be 12% per annum to be computed from default, i.e., from judicial or extrajudicial demand under and subject to the provisions of Article 1169 of the Civil Code. (Eusebio-Calderon v. People, G.R. No. 158495, October 21, 2004, 441 SCRA 137; Eastern Shipping Lines, Inc. v. CA, G.R. No. 97412, July 12, 1994, 234 SCRA 78; Garcia v. Thio, G.R. No. 154878, March 16, 2007).
Hence, the debtor is liable for the payment of legal interest per annum to be computed from the date when she received the demand letter. From the finality of the decision until it is fully paid, the amount due shall earn interest at 12% per annum, the interim period being deemed equivalent to a forbearance of credit. (Cabrera v. People, G.R. 150618, July 24, 2003, 407 SCRA 247; Garcia v. Rica Marie Thio, G.R. No. 154878, March 16, 2007).
On the payment of interest, the 12% rate is applied only when the obligation breached consists in the payment of a sum of money, i.e., forbearance of money, in the absence of a stipulation. Otherwise the applicable rate is 6% per annum. Upon the finality of this ruling, the rate of interest shall be 12% per annum for the entire judgment, until its satisfaction. (United Planters Sugar Milling, Inc. v. CA, et al., G.R. No. 126890, November 28, 2006).