I placed this in the marketing forum and have had no answers - so thought maybe it would be addressed here.

When calculating an APR for an advertisment are we required to use a 12 month term for the calculation or should you use a term that you offer - example 48 mos? As we know the longer the term the less the APR.

You should give an example...so if that's the best example, that's what I would use.

(2) Additional terms. An advertisement stating any of the terms in paragraph (d)(1) of this section shall state the following terms, as applicable (an example of one or more typical extensions of credit with a statement of all the terms applicable to each may be used):

(i) The amount or percentage of the downpayment.

(ii) The terms of repayment, which reflect the repayment obligations over the full term of the loan, including any balloon payment.

(iii) The “annual percentage rate,” using that term, and, if the rate may be increased after consummation, that fact.

I didn't notice that you double posted this question here after 2 hours, but have moved my comments here:

Where are you getting anything about 12 months? If you are advertising open-end credit the rule is:

Section 1026.16(a) Actually available terms.
If an advertisement for credit states specific credit terms, it shall state only those terms that actually are or will be arranged or offered by the creditor.

If it's closed-end, the rule is:

Section 1026.24(a) Actually available terms.
If an advertisement for credit states specific credit terms, it shall state only those terms that actually are or will be arranged or offered by the creditor.