Two compulsory-use protections sit in the statute, and both are narrower and more precise than the versions people repeat. 15 USC 1693k provides that no person may (1) condition the extension of credit to a consumer on that consumer's repayment by means of preauthorized electronic fund transfers, or (2) require a consumer to establish an account for receipt of electronic fund transfers with a particular financial institution as a condition of employment or receipt of a government benefit. Regulation E carries the same two limbs at 12 CFR 1005.10(e).
Read the second one closely, because it is routinely overstated. What it prohibits is being told where to hold the account. It does not, on its own terms, prohibit an employer from paying electronically rather than by paper check. Whether an employer may require electronic payment at all, and what alternatives it must offer, is a matter of state wage-payment law, which differs from state to state. So the reliable statement is that you get to choose the institution; whether you get to insist on paper is a question for your state's rules and your employer's policy.
The first limb is the one that shows up in lending rather than in payroll. A lender may offer a rate discount for enrolling in autopay, and commonly does, but it may not make repayment by preauthorized electronic transfer a condition of the credit itself.
Government benefit payments carry an extra, explicit disclosure. Where a government agency distributes benefits through a prepaid card account, 12 CFR 1005.15(c)(2)(i) requires the agency's pre-acquisition disclosure to include a statement that the consumer does not have to accept the card, using the clause "You do not have to accept this benefits card. Ask about other ways to receive your benefits," or a substantially similar one, or alternatively to list the options available and invite the recipient to choose. A benefit recipient handed a card therefore has a stated right to ask what else is on offer, which for most programs includes deposit to an account of their own choosing. The section reaches government benefit accounts generally and excludes needs-tested benefits under a program established by state or local law or administered by a state or local agency, so the disclosure is not universal across every benefit a household might receive.
The notice rule is what tells you a deposit arrived, and it has three compliance routes. Under 12 CFR 1005.10(a)(1), where a person initiates preauthorized transfers to a consumer's account at least once every 60 days, the account-holding institution must give the consumer positive notice within two business days after the transfer occurs, or negative notice within two business days of the scheduled date that it did not occur, or provide a readily available telephone line the consumer may call to find out, with the number disclosed both in the initial account terms and on every periodic statement. 1005.10(a)(2) removes the obligation entirely if the payer itself gives positive notice, which is why a payroll notification from an employer satisfies the rule and why many banks rely on the telephone-line option.
The crediting rule is the timing floor, and it is worth knowing before planning around an "early" payday. 1005.10(a)(3) requires an institution that receives such a transfer to credit it as of the date the funds for the transfer are received. That is a rule about when the money counts, not a promise that it will appear before then. Institutions that make payroll available a day or two ahead of the stated payday are advancing funds voluntarily, as a product feature that can be changed or withdrawn, so a bill scheduled on the assumption of early availability is resting on a courtesy rather than on a right.
An incorrect deposit is a Regulation E error, which gives you a process rather than only a phone call. 12 CFR 1005.11(a)(1)(ii) defines an error to include an incorrect electronic fund transfer to or from the consumer's account, so a deposit in the wrong amount is within the procedure, not just a debit. So is a transfer not identified in accordance with the notice rule, under 1005.11(a)(1)(vi), and so is a request made simply to determine whether an error exists, under (a)(1)(vii). Notice may be given orally, and the institution then works to a defined investigation timetable. None of that displaces the practical point that a payroll error was made by the payer and will usually be fixed by the payer, but it does mean the receiving bank has obligations too.
Why it is the anchor of a banking relationship rather than a convenience. Institutions commonly waive a checking account's monthly maintenance fee for customers receiving direct deposit, which makes the deposit instruction the thing a new bank asks you to move and the thing an old bank is quietly relying on. That has two consequences worth planning for. Changing jobs breaks the instruction, and the fee waiver goes with it. And splitting a deposit across accounts reduces what lands in each, so a waiver measured against a minimum monthly deposit into one account can lapse without your pay changing at all.
The contrast with depositing a check is availability rather than safety. A direct deposit is credited as of receipt of funds. A deposited check is subject to Regulation CC's availability schedule, which is expressed in business days and switches off in several situations, including new accounts, unusually large deposits, redeposited checks, repeatedly overdrawn accounts, and a reasonable cause to doubt collectibility. The next-business-day treatment often described for cashier's, certified and teller's checks also carries conditions, one of which is that the deposit be made in person to an employee, so a mobile or ATM deposit of the same instrument does not qualify. Availability is also not collection: funds made available can still be charged back if the check is returned.