Okay- this is may be a stupid question to most of you but I have to ask. Does Regulation E error resolution requirements apply to a line of credit, such as a overdraft LOC, or any other credit product.

For example if a customer is disputing an electronic transfer from a line of credit does Reg E apply or is this a Reg Z issue?

Regulation E covers EFTs in consumer asset accounts -- that generally means only deposit accounts. It does not cover transactions in a line of credit or other credit account.

I think it falls under Reg Z.

But remember that debits to loans are not permitted in the ACH system (unless it's a reversal of a credit entry). At my former employer, those items would reject and had to be special handled. Often times, the branch of account was contacted to approve the transactions by getting hold of the customer. If there was a name discrepancy, the item was returned. Most times, all we saw were converted checks (ARC, POP, BOC, etc.) and those were easier to confirm - check sequence.

Thank you both for your response. In the commentary to Reg E it states:

12(a) Relation to Truth in Lending
1. Determining applicable regulation. i. For transactions involving access devices that also function as credit cards, whether Regulation E or Regulation Z (12 CFR part 226) applies depends on the nature of the transaction. For example, if the transaction solely involves an extension of credit, and does not include a debit to a checking account (or other consumer asset account), the liability limitations and error resolution requirements of Regulation Z apply. If the transaction debits a checking account only (with no credit extended), the provisions of Regulation E apply. If the transaction debits a checking account but also draws on an overdraft line of credit attached to the account, Regulation E's liability limitations apply, in addition to §§226.13 (d) and (g) of Regulation Z (which apply because of the extension of credit associated with the overdraft feature on the checking account). If a consumer's access device is also a credit card and the device is used to make unauthorized withdrawals from a checking account, but also is used to obtain unauthorized cash advances directly from a line of credit that is separate from the checking account, both Regulation E and Regulation Z apply.
2. Issuance rules. For access devices that also constitute credit cards, the issuance rules of Regulation E apply if the only credit feature is a preexisting credit line attached to the asset account to cover overdrafts (or to maintain a specified minimum balance). Regulation Z (12 CFR part 226) rules apply if there is another type of credit feature, for example, one permitting direct extensions of credit that do not involve the asset account.

So in this case Reg E would apply if we permit a debit card to pull funds from an overdraft line of credit. Correct?

From your above citation:

If the transaction debits a checking account but also draws on an overdraft line of credit attached to the account, Regulation E's liability limitations apply, in addition to §§226.13 (d) and (g) of Regulation Z (which apply because of the extension of credit associated with the overdraft feature on the checking account).