What the statement is required to show. For a consumer account to or from which electronic fund transfers can be made, 12 CFR 1005.9(b) requires the institution to send a periodic statement for each monthly cycle in which an electronic fund transfer occurred, and at least quarterly if none occurred. The statement must set out, for each transfer, the amount, the date it was credited or debited, the type of transfer and the account, the terminal location for a consumer-initiated terminal transfer, and the name of any third party involved. It must also show the account number, the amount of any fees assessed during the period for transfers, for the right to make transfers, or for account maintenance, the balances at the beginning and the close of the period, and an address and telephone number for inquiries and error notices.
Article 4 adds a separate requirement about the underlying paper. Under UCC 4-406(a), as adopted in most states, a bank that sends a statement of account showing payment of items must either return the items or make them available, or else provide information in the statement "sufficient to allow the customer reasonably to identify the items paid." The provision goes on to say that item number, amount and date of payment are sufficient, which is why modern statements list check numbers rather than returning canceled checks. If the items are not returned, UCC 4-406(b) requires the person retaining them to keep either the items or the capacity to furnish legible copies for seven years, and to supply a copy on request within a reasonable time.
Two clocks run on the same document, and which one applies turns on how the money left the account. This is the single most useful thing to understand about a bank statement, and almost nothing written for consumers says it.
For a forged signature or an altered paper item, the governing rule is UCC 4-406. Subsection (c) requires the customer to "exercise reasonable promptness in examining the statement or the items," and to notify the bank promptly of anything the examination should reasonably have revealed. Subsection (d) sets the consequence of failing that duty, and it has two limbs. Under (d)(1), the customer cannot assert the unauthorized signature or alteration on that item if the bank also proves it suffered a loss because of the failure. Under (d)(2), and this is the harsher one, the customer cannot assert the same wrongdoer's later forgeries or alterations on any other item the bank paid in good faith before being notified, once the customer has had "a reasonable period of time, not exceeding 30 days," to examine the statement and report. The point of that rule is serial fraud: an employee or family member forging a run of checks. The first one is arguable; the ones cashed after your review window closed generally are not. Subsection (e) can still divide the loss where the customer proves the bank failed to exercise ordinary care, and the preclusion falls away entirely if the customer proves the bank did not pay in good faith. Subsection (f) then sets an absolute outer limit, without regard to anyone's care: a customer who does not discover and report an unauthorized signature or alteration within one year after the statement or items were made available is precluded from asserting it at all.
One qualification applies to all of that. Article 4 is a uniform act, not a federal statute: it binds only as each state enacted it, and states do vary in their amendments. And UCC 4-103(a) lets the parties vary Article 4 by agreement, so a deposit agreement can set the standard by which the customer's examination duty is measured, provided the standard is not manifestly unreasonable and the bank does not disclaim its own good faith or ordinary care. So the periods above are the uniform text, and the operative version is the one in the state whose law governs the account, as modified by the account agreement.
For an unauthorized electronic transfer, the governing rule is Regulation E, and the clock is different. Under 12 CFR 1005.6(b)(3), a consumer must report an unauthorized transfer appearing on a periodic statement within 60 days of the institution's transmittal of that statement in order to avoid liability for later transfers. Separately, 12 CFR 1005.11(b)(1)(i) requires the institution to investigate any notice of error received no later than 60 days after it sent the statement on which the error first appeared. The liability ladder underneath those deadlines is covered on the debit card page, which quotes it in full.
The gap between the two regimes is why the medium matters. A check forged against your account and a card transaction you did not make appear on the same page of the same document and are governed by different law with different deadlines. When something is wrong, the practical move is to report it in writing immediately rather than to work out which regime applies first.
Reconciling is what makes any of this operative. A statement you have received but not read gives you no protection, because both regimes are built around what a reasonable examination would have revealed. Reconciliation is the procedure that turns receipt into examination: compare your own record of what should have happened against the institution's record of what did, resolve every difference, and end with two numbers that agree for a stated reason. It catches three distinct things that nothing else catches, and they are worth separating. The first is items you never recorded, most often a fee or an automatic charge. The second is timing, meaning items you recorded that have not yet posted. The third is items you did not authorize at all, which is the whole point of the deadlines above.
How long to keep them. There is no single federal retention period for a consumer. What there are, are downstream deadlines that a statement may be the only proof for: the seven-year window in which the bank must be able to furnish a copy of a paid item, the periods in which the Internal Revenue Service may examine a return, and the documentation a lender or a court may ask for. For a business the calculus is different again, because the statement is a source document for the books rather than a personal record.
