Who and what the rule reaches. Regulation E defines "consumer" at § 1005.2(e) as a natural person, and "account" at § 1005.2(b)(1) as a demand deposit, savings or other consumer asset account "held directly or indirectly by a financial institution and established primarily for personal, family, or household purposes." Those two definitions do most of the work: a sole proprietor's business checking account is outside the rule even at the same bank, and so is a transfer between two companies. "Financial institution" at § 1005.2(i) is broader than "bank": it reaches any person that holds a consumer's account or that issues an access device and agrees to provide electronic fund transfer services, which is how a payment app can find itself inside the rule.
The two subparts. Subpart A is the general rule, §§ 1005.1 to 1005.20, and it is what people mean by Regulation E in ordinary conversation: disclosures, the issuance of cards and codes, consumer liability for unauthorized transfers, receipts and statements, preauthorized transfers, error resolution, ATM notices, overdraft services, prepaid accounts and gift cards. Subpart B, §§ 1005.30 to 1005.36, is a separate regime for remittance transfers, which is the rule that governs sending money abroad from a consumer account.
The error-resolution procedure, which is the part most worth knowing. Section 1005.11 is the machinery a consumer actually uses, and it is considerably more specific than "the bank will look into it."
It starts with what counts as an error. Under § 1005.11(a)(1) an error is an unauthorized electronic fund transfer; an incorrect transfer to or from the account; the omission of a transfer from a periodic statement; a computational or bookkeeping error by the institution; receiving the wrong amount of money from an electronic terminal; a transfer not identified as the documentation rules require; or a request for that documentation, or for information or clarification, including a request made simply to find out whether an error exists. Paragraph (a)(2) excludes three things that are not errors: a routine balance inquiry, a request for information for tax or recordkeeping purposes, and a request for duplicate copies of documents.
Then the clocks start, and there are two routes through them. Under § 1005.11(c)(1) the institution must investigate promptly and determine whether an error occurred within ten business days of receiving the notice, report the result to the consumer within three business days of finishing, and correct the error within one business day of deciding one occurred. If it cannot finish in ten business days, § 1005.11(c)(2) lets it take up to 45 days from receipt instead, but only on conditions. It must provisionally credit the disputed amount, with interest where applicable, within those same ten business days; it must tell the consumer of the amount and date of that credit within two business days of making it; and it must give the consumer full use of the money while the investigation runs. The price of more time is that the consumer holds the money in the meantime rather than the institution.
Three details inside that route are easy to miss and each of them matters. The institution may withhold a maximum of $50 from the provisional credit where it has a reasonable basis for believing an unauthorized transfer occurred and it has met the disclosure preconditions in § 1005.6(a). It need not provisionally credit at all if it required written confirmation of an oral notice and did not receive it within ten business days, or if the alleged error involves an account subject to Regulation T, the Federal Reserve Board's rule on securities credit by brokers and dealers. And § 1005.11(b)(2) is what allows that first condition: an institution may require written confirmation of an oral notice of error within ten business days, but only if it told the consumer of the requirement and gave the address when the oral notice was given.
The extensions, and the one that covers most card disputes. Section 1005.11(c)(3) lengthens both clocks in specific situations. Twenty business days replace ten where the disputed transfer happened within 30 days of the first deposit to a new account. Ninety days replace 45 for completing an investigation where the transfer was not initiated within a state, resulted from a point-of-sale debit card transaction, or occurred within 30 days of the first deposit. The middle limb is the one to notice, because an ordinary disputed debit card purchase falls inside it: the outer limit on that dispute is 90 days, not 45. The Official Interpretations draw the boundary of that limb precisely. Comment 11(c)(3)-1 says the extended deadlines "apply to all debit card transactions, including those for cash only, at merchants' POS terminals, and also including mail and telephone orders," and then says they "do not apply to transactions at an ATM, however, even though the ATM may be in a merchant location." So a disputed online purchase gets the longer outer limit and a disputed ATM withdrawal does not.
What happens if the institution decides there was no error. Section 1005.11(d) requires a written explanation of the findings and a statement of the consumer's right to request the documents the institution relied on, which it must then provide promptly. If it debits a provisional credit it has to notify the consumer of the date and amount, and it must honor checks, drafts and preauthorized transfers for five business days after that notification without charging an overdraft fee, to the extent it would have paid them had the credit not been taken back. Under § 1005.11(e), an institution that has fully complied has no further duty if the consumer later reasserts the same error, with one exception written into the paragraph: it does not close off an error the consumer asserts after receiving documentation or information they had requested under § 1005.11(a)(1)(vii).
What Regulation E does not do, which is where most of the disappointment comes from. It sets a ceiling on what a consumer can be charged for an unauthorized transfer, and Supplement I comment 6(b)-3 says plainly that "no agreement between the consumer and an institution may impose greater liability on the consumer for an unauthorized transfer than the limits provided in Regulation E." It says nothing about a transfer the consumer authorized, which is the shape of most modern schemes. Section 1005.3(c) then excludes several things outright, including any transfer originated by "check, draft, or similar paper instrument" and any transfer "through Fedwire or through a similar wire transfer system that is used primarily for transfers between financial institutions or between businesses." And a business account is outside the rule entirely. Those limits are the reason the same loss can be fully reversible on one rail and unrecoverable on another.