Who Regulation E binds, and the definition is the point. Under 12 CFR 1005.16(a), an "automated teller machine operator" means "any person that operates an automated teller machine at which a consumer initiates an electronic fund transfer or a balance inquiry and that does not hold the account to or from which the transfer is made, or about which an inquiry is made." Read the final clause. The machine-side notice duty is defined by not holding the account, so it can never attach to the cardholder's own bank. That definitional choice explains the asymmetry people notice at the machine without being able to name it.
The asymmetry is about place and timing rather than about secrecy, and getting that right matters. The cardholder's own institution is not exempt from disclosure: 12 CFR 1005.7(b)(5) requires its initial disclosures to state "Any fees imposed by the financial institution for electronic fund transfers or for the right to make transfers", and an out-of-network withdrawal is such a transfer. Regulation DD separately requires the fee to appear in the account's deposit disclosures. What the cardholder's institution never has to do is put its number in front of the cardholder at the machine, in the moment, with a chance to back out. The operator has to do exactly that. So both charges are disclosed somewhere; only one is disclosed where the decision is made.
What the operator has to do, and what happens if it does not. Section 1005.16(b) requires an operator imposing a fee to give a notice disclosing "the amount of the fee". Under (c) that notice may appear on the machine's screen or on paper, but either way it must come "before the consumer is committed to paying a fee". And (d) is the enforcement limb worth knowing: an operator "may impose a fee on a consumer for initiating an electronic fund transfer or a balance inquiry only if" the notice was given and "the consumer elects to continue the transaction or inquiry after receiving such notice." An undisclosed operator surcharge is therefore not lawfully imposable, and the cancel button on the fee screen is the election the rule contemplates rather than a courtesy.
The commentary closes the obvious workaround. A fee shown on the receipt cannot satisfy the paper alternative, "if the receipt is provided at the completion of the transaction because, pursuant to the statute, the paper notice must be provided before the consumer is committed to paying the fee" (comment 9(a)(1)-2(ii)). Disclosure after the money has been dispensed is not disclosure for this purpose. One piece of long-circulating guidance is out of date here: the requirement for a physical placard on or at the machine was removed when the regulation was amended in 2013 to conform to Public Law 112-216, which had struck the statutory on-or-at-the-machine notice (78 FR 18221, March 26, 2013), which the Cash Flow pillar covers, so the absence of a sticker tells a cardholder nothing. The staleness is worth knowing about because it survives inside the official text: Regulation E's own commentary at comment 9(a)(1)-2(i) still describes 1005.16 as requiring disclosure "both on a sign on or at the terminal ... and on the terminal screen", which the section itself has not required since 2013. Where commentary and regulation disagree, 1005.16(c) is the operative text.
A balance inquiry is a chargeable event, and the rules point in opposite directions on it. Section 1005.16 covers "an electronic fund transfer or a balance inquiry" throughout, so the operator's notice-and-election requirement applies to checking a balance just as it applies to taking cash. But the commentary to a different provision, the initial disclosures an institution gives its own customers under 1005.7(b)(5), says an institution "is not required to disclose fees for inquiries made at an ATM since no transfer of funds is involved", and adds a cross-reference to Regulation DD. The same commentary notes that minimum-balance fees, stop-payment fees and overdraft fees may, but need not, be disclosed under Regulation E. So the operator must tell you about an inquiry fee at the machine, while your own institution need not list inquiry fees in its Regulation E disclosures at all. Both charges are real; only one of them is announced where the decision is made.
One cost of an ATM that is not a fee. Regulation CC gives cash deposited "in person to an employee of the depositary bank" next-business-day availability, and gives the bank until the second business day where the cash is not deposited in person to an employee (12 CFR 229.10(a)(1) and (2)). Depositing cash at a machine rather than at a counter therefore costs a day even where it costs nothing.