An external account is any bank or financial account held at a different institution from the one you’re currently logged into. So what does an external account mean in practice? It means the account sits on another company’s books, and if you want to move money between it and the platform you’re using, you have to link the two first. The link takes a few minutes to set up, plus a short verification period before transfers can start.
Why the Label Is Relative
“External” is a point-of-view word. A savings account at an online bank is an internal account when you log into that bank’s app, and it becomes an external account the moment you try to connect it from your brokerage, credit union, or a different bank’s platform. Both accounts usually belong to you. The distinction is about which institution manages the ledger, not who owns the money.
Each institution operates under its own charter and keeps its own records. Linking accounts does not merge them legally or change where they’re insured. The FDIC insures deposits at each separately chartered bank up to the standard maximum, and accounts at different banks receive independent coverage.1FDIC. General Principles of Insurance Coverage
Why People Link External Accounts
Most people link an external account so they can move money without visiting a branch or writing a check. Common uses include:
- Funding a high-yield savings account at a bank that pays a better rate than your everyday checking bank.
- Sending cash to a brokerage or robo-advisor whose custodian is a separate institution.
- Paying a credit card, mortgage, or auto loan held at a different lender.
- Pulling balances from multiple banks into one primary account.
These transfers usually travel through the Automated Clearing House (ACH) network, which processes payments in batches rather than in real time. Standard ACH is free at many banks and settles in one to three business days.2Federal Reserve Financial Services. FedACH Processing Schedule A domestic wire transfer often arrives the same day, but consumers commonly pay $20 to $35 to send one. Same-day ACH is available for eligible payments up to $1 million per transaction, though not every bank offers it on consumer accounts.3Nacha. ACH Payments Fact Sheet
What You Need to Link One
To create the link, you need two pieces of information from the external account:
- The nine-digit routing number, which identifies the bank or credit union. It appears at the bottom left of a paper check and inside the external bank’s online portal. The American Bankers Association assigns these numbers, and only federally or state-chartered institutions eligible for a Federal Reserve master account can receive one.4American Bankers Association. ABA Routing Number
- The account number, which pinpoints your specific account at that bank. It appears on your statements and usually in your online banking dashboard.
You’ll also specify the account type: checking, savings, or money market. Copy the numbers exactly. A single wrong digit can send money to the wrong account or cause the transfer to fail.
Most platforms only let you link accounts you personally own. For a joint account, both names generally must match. Business and personal accounts usually cannot be cross-linked, because the ownership names don’t match.
How Verification Confirms You Own the Account
Before you can move money, the platform has to confirm you actually control the external account. Two methods are common.
Instant Verification
Many platforms use a third-party aggregator. You log in to your external bank through an encrypted connection, the aggregator confirms the account exists and belongs to you, and the link activates immediately. It’s fast, but it means sharing your bank login credentials with a third party.
Micro-Deposit Verification
If you’d rather not share your login, the requesting institution can send two small deposits, each under $1.00, to your external account. They typically arrive within one to three business days.5U.S. Bank. What Are Microdeposits? You log back in to the requesting platform, enter the exact cent values, and the link completes. Some institutions give you a limited window, often around 15 days, to confirm the amounts before the attempt expires.
Transfer Limits, Timing, and Fees
Once the link is active, you can start sending and receiving funds. Banks set their own daily, per-transaction, and monthly caps on ACH transfers. Limits vary widely, from as low as $1,000 per transaction at some institutions to $25,000 or more per day at others. Check your bank’s policy before scheduling a large move. If you need to send more than your limit allows, you may have to split the transfer across multiple days or ask for a temporary limit increase.
Standard ACH usually settles on the next business day, though your bank may hold funds for another day or two before making them available.2Federal Reserve Financial Services. FedACH Processing Schedule
Watch for a few fees that can surprise you:
- Outgoing transfer fees, especially for expedited or same-day delivery. Check both the sending and receiving institution’s schedules.
- Stop payment fees on a pending or recurring ACH, often in the range of $15 to $36.
- Returned-item fees from either bank when a transfer fails for insufficient funds or wrong account details.
- Wire fees of $20 to $35 for a domestic outgoing wire, if you bypass ACH.
Your Protections if Something Goes Wrong
Electronic transfers between linked accounts are covered by the Electronic Fund Transfer Act and its implementing regulation, Regulation E.6eCFR. 12 CFR 1005.6 – Liability of Consumer for Unauthorized Transfers If someone makes an unauthorized transfer from your account, your financial liability depends on how quickly you report it:
- Report within 2 business days of learning about the loss, and your maximum loss is $50 or the amount transferred before you notified the bank, whichever is less.
- Report after 2 business days but within 60 days of your statement, and the cap rises to $500.
- Report after 60 days from your statement date, and you could lose the entire amount of any unauthorized transfers that occurred after that 60-day window. There’s no cap.
The 60-day rule is the one most people miss. Even if you didn’t cause the problem, failing to review statements and report unauthorized activity within 60 days can leave you responsible for every dollar taken after that deadline.7Office of the Law Revision Counsel. 15 U.S. Code 1693g – Consumer Liability Review statements from every linked account at least monthly, and contact your bank by phone the moment you spot a problem. Regulation E also requires the bank to investigate errors within specific timeframes.
The Credential-Sharing Question
Instant verification is convenient, but it means typing your bank username and password into a third-party aggregator’s system. These services often use screen scraping, which logs into your bank on your behalf and reads your data, sometimes pulling more than just the account number, including transaction history and balances.
The risk is that third-party aggregators are not always held to the same federal data-protection standards as your bank. If an aggregator suffers a breach, your information could be exposed, and the remedies available to you may be more limited than they would be with a regulated bank.
A few ways to reduce your exposure:
- Choose micro-deposits when the option is available. That method never requires sharing your login.
- Review connected apps regularly. Most banks now let you see which third-party services have access to your account data under a “manage third-party access” or “data sharing” option.
- Revoke access you no longer need. If you linked an account for a one-time transfer, disconnect it once you’re done.
- Change your bank password after revoking access, for an extra layer of protection.
How the CFPB’s Data Rights Rule Will Change Linking
The Consumer Financial Protection Bureau finalized its Personal Financial Data Rights rule under Section 1033 of the Dodd-Frank Act, and it will reshape account linking over the next several years.8CFPB. CFPB Finalizes Personal Financial Data Rights Rule Under the rule, banks and financial providers must share your account data, including transaction information, balances, and payment details, with a third party you authorize, at no cost to you.
The rule also adds consumer protections. Third parties can only collect and use your data to deliver the specific product you requested; they cannot harvest it for unrelated purposes like targeted advertising. You gain the right to revoke access at any time, and revocation has to be simple rather than buried in settings. Once you revoke access, the third party must delete your data by default. Authorization expires after one year unless you actively renew it.
Compliance phases in by institution size. Banks with $250 billion or more in assets must comply by April 1, 2026. Banks with $10 billion to $250 billion in assets have until April 1, 2027, and smaller institutions have later deadlines extending to April 1, 2030.9CFPB. Section 1033.121 Compliance Dates As those deadlines arrive, linking an external account should become more standardized and less dependent on sharing your bank password.