Micro-deposit verification: How it works and when to use it

Micro-deposit verification confirms that a user can access a bank account by sending a small deposit, usually under $1, and asking them to report the deposit amount or a code back to the sender. Micro-deposits have provided secure account verification for decades. Traditionally, they’ve been seen as an undesirable backup choice, used only when users choose not to verify their account with their bank details or when their bank isn’t supported by open banking.

However, new technology is changing that, making micro-deposits faster and more secure. Verification that once took several days can now happen in under 10 seconds, depending on the payment rail used. Learn how micro-deposits work and how emerging payment rails are making them more efficient and secure.

Key takeaways 

• Micro-deposit verification confirms a user can access a bank account by sending a small deposit and asking the user to verify the deposit amount or a code.

• Verification speed now ranges from under 10 seconds with RTP or FedNow to 1–3 business days with standard ACH.

• Micro-deposits remain one of the primary methods for verifying a bank account, alongside instant credential-based verification and database verification. 

• Instant micro-deposits are available for roughly 75% of accounts, while ACH micro-deposits remain available for 100% of US bank accounts. 

• Plaid's Instant Auth covers approximately 95% of consumers' bank accounts, with micro-deposits serving as the universal fallback for accounts not covered by open banking.

What is micro-deposit verification, and how does it work?

Micro-deposits are small transactions, typically under $1, that financial companies send to verify that an account is valid and the user can access the account. This process is often used to verify an account for payments and new account funding. It’s a secure way to verify bank account information and ensure money can be sent to or pulled from the correct account.

Here’s how micro-deposit verification works: 

1. Account and routing numbers are submitted. Users are prompted to provide their account number and routing number. 

2. A small deposit is sent via Automated Clearing House (ACH), Real Time Payments (RTP), or FedNow. The financial institution or fintech app sends a transaction of a few cents in two deposits. With Plaid, users receive a single one-cent transaction with a verification code included in the transaction description. Using a code with a tiny amount disincentivizes fraudsters who attempt to spam micro-deposit flows and doesn’t require the additional step of withdrawing the micro-deposit. 

3. The user confirms the amounts or a code. The user will log into their account to find the exact amounts deposited or a verification code and enter them where instructed. In manual verification, the user looks up and reports the amount or code themselves. With automated micro-deposits, the sender checks the transaction directly and confirms the deposit without user involvement. Plaid offers this to any bank where credential connection is supported. 

4. The account is linked. If the code or deposit amounts are correct, the account is verified.

5. Deposits are reversed or absorbed as a verification cost. Traditionally, the app will withdraw the amount deposited.

While micro-deposits aren't new, they're gaining attention with the release of instant payment rails like Real-Time Payments and FedNow. Plaid, for example, uses an instant micro-deposit tool that can verify accounts on RTP or FedNow in seconds. If those payment rails aren’t available, it falls back to same-day ACH, which is available to all US bank accounts. 

How long does micro-deposit verification take?

Verification speed depends on which payment rail sends the deposit:

• Instant (RTP or FedNow): Under 10 seconds; available for roughly 75% of accounts. 

• Same-day (Same-Day ACH): A few hours to one business day; available to all US bank accounts.

• Standard (ACH): 1 to 3 business days; available to all US bank accounts.

That’s a significant shift from legacy ACH clearing timelines of up to five business days, which is what made micro-deposits feel slow and outdated in the first place. Plaid’s same-day and instant options are a genuine speed differentiator. Instead of making every user wait multiple days, Plaid automatically routes eligible users to the fastest rail their bank supports.

Is micro-deposit verification safe?

Yes, micro-deposit verification is a secure, well-established method for confirming account access. However, fraud can occur when a scammer already has a victim’s account and routing number and uses them to link the account to an outside platform. The scammer then contacts the victim, posing as the bank or the app, and asks them to read back the deposit amounts. If the victim complies, the scammer completes the verification and gains the ability to move money through the newly “verified” connection.

An account verified through fake micro-deposits appears identical to a legitimately verified one in a system’s records, so the resulting fraud can surface well after the original micro-deposit is posted. Watching for unusual patterns, such as repeated micro-deposit attempts tied to a single device or IP address, is one way institutions can catch this activity before it results in a loss.

Micro deposits vs. other verification methods

When it comes to verifying account access, there are three primary methods: 

• Micro-deposits: Small transactions are sent to verify that an account is valid and the user can access the account. 

• Credential-based authentication: Where the user verifies with their bank account username and password.

• Database validation: Checks the user's account information against proprietary data.

Micro-deposits 

Micro-deposits offer a reliable fallback option when the primary goal is to confirm access to the bank account. They are universally accessible, meaning this method can be used for accounts with all institutions. However, even with RTP and FedNow, micro-deposits are only used to connect accounts for payments. Only credential-based authentication can link accounts to share data like transaction history, which many fintech apps need to provide services to their users.

There are some user experience challenges, such as if the user forgets to verify the transaction. There are also some fraud risks associated with micro-deposits. For example, a bad actor may trigger them a thousand or more times to increase the account's balance, creating returns or overdrafts when attempting to pull back the deposits.

Credential-based authentication

Credential-based authentication provides immediate access to account verification. The process takes less than a minute and provides access to additional account data. Apps and financial institutions use this data to assess risk, power lending, or tools such as budgeting and wealth management. Not all institutions can verify with credential-based logins, and some users may not want to use them. 

Database validation

Database validation uses a data source to provide instant confirmation of whether an account is valid and in good standing. The process is often completed in seconds, with a simple user experience, but gaining viable coverage across most US bank accounts is challenging. This results in apps taking on a higher risk of transacting with unverified accounts.

Plaid also offers account verification through our Database Auth product to check submitted account details against the Plaid network itself (a database of more than 260+ million verified accounts) in addition to routing number formatting rules. That provides Database Auth with a stronger, first-party data source for confirming an account is valid before a user ever needs to resort to micro-deposits.

When should companies use micro-deposit verification instead of Instant Auth?

Even with the coverage Instant Auth provides, there are specific situations where micro-deposit verification is the better fit:

• The user declines credential-based verification. Some users don’t want to share their bank login credentials with a third party, regardless of how secure the connection is, and need a manual alternative.

• The institution isn’t covered by instant or open banking connections. Smaller banks and credit unions that don’t support credential-based login still need a reliable way to verify accounts.

• The product needs guaranteed universal coverage. Micro-deposits work with any US bank account, making them a necessary fallback for products that can’t afford to turn away a user based on their bank.

Are micro deposits still relevant?

Despite the rise of new authentication methods, micro-deposits continue to be important. 

Plaid’s Instant Auth coverage is extensive, with over 95% of consumers with a supported bank account that can be instantly verified. However, some users prefer manual verification methods over instant authentication methods for data sharing sensitivity or simply cannot remember their banking credentials. Same-Day Micro-deposits also provide a universal method to verify accounts for institutions that aren’t connected to open banking.

Rail coverage still varies, too. Instant micro-deposits are currently available for roughly 75% of accounts, while manual ACH micro-deposits remain available for 100% of US bank accounts. That gap is exactly why micro-deposits still matter as a universal fallback, even as instant options expand.

Same-day ACH, RTP, and FedNow are bringing micro-deposits into the 21st century. These new payment rails reduce the time for micro-deposit verification to within 10 seconds with RTP and FedNow or within a few hours with Same-day ACH.

How technology is improving micro deposits 

Some of the cons of micro deposits are being eliminated with RTP and FedNow. These payment rails enhance their usability and allow services to verify accounts in seconds. For institutions that aren’t connected to RTP or FedNow, same-day ACH can serve as a fallback option, taking four hours to one business day. 

However, even with RTP and FedNow, micro deposits are only used to connect accounts for payments. Only credential-based authentication can link accounts to share data like transaction history, which many fintech apps need to provide services to their users. 

Another technological improvement is automated micro deposits. These allow verification without user involvement. Plaid offers these to any bank where credential connection is supported. The user only needs to provide their account numbers; Plaid then sends a deposit and uses our Transactions product to verify the specific deposit has landed in that account.

Additionally, unlike traditional micro deposits Plaid only uses a single micro deposit of one cent and permits users to to verify with a code, rather than the amount. Using a code with a tiny amount disincentivizes fraudsters who attempt to spam micro-deposit flows and does not require the additional step of withdrawing the micro deposit. 

How Plaid micro deposits increase conversion 

Many financial institutions have built their own micro-deposit flows as fallbacks. Plaid's solutions for micro-deposit authentications convert better than in-house flows. They also do more to protect against fraud.

Plaid uses smart routing to send users to the highest converting and optimal payment rail (RTP, FedNow, or same-day ACH) for their bank. Also, the Reroute to Credentials feature nudges users back into credential-based verification. If the user chooses to proceed manually, Plaid will allow them to use instant micro-deposits if their bank supports the instant rails.

For implementation details, see the Auth product documentation.

The future of account verification is 100% instant coverage 

In the evolving account verification and micro deposits space, Plaid is committed to providing 100% instant coverage and the best user experience. New instant payment rails create a micro deposit method that wasn't available before and fallbacks for credential-based authentication could take days. Now, the fallback can be instant or at least take place within the same day. 

Instant payments and automation have transformed micro deposit's speed and reliability. We are on the road to 100% instant account verification coverage, no matter the path the user chooses.

→ Learn more about Plaid’s payments solution.