How Bank Sweep Networks
Extend FDIC Coverage to $5M
IntraFi ICS, CDARS, fintech partner-bank programmes. What they actually do, how they price, who runs them, and the structural risk the 2023 Synapse failure exposed.
The mechanism in one paragraph
A sweep network splits a single customer deposit across many FDIC-member banks in increments below the $250,000 per-ownership-category insurance cap, so that every dollar is fully insured. The customer interacts with one originating bank (or one fintech), sees a single account balance, and gets a single 1099-INT at year-end. Behind the scenes, the network operator (most commonly IntraFi) allocates the funds across partner banks each business day and reconciles balances. Each partner bank holds its allocated portion as a normal FDIC-insured liability. The customer's coverage scales with the number of participating partner banks, currently capped at $5 to $6 million for the common fintech business accounts, and effectively unlimited for traditional bank IntraFi ICS clients with sufficient operating sophistication.
How IntraFi ICS actually allocates a deposit
Walk through a $2 million deposit at a community bank that offers IntraFi ICS. On day 1, the customer deposits $2 million via wire. The originating bank retains a portion (up to $250,000) in its own books. IntraFi's allocation engine identifies 7 partner banks willing to accept deposits that day, considering rate competition, FDIC capacity, and the customer's exclusion list (a customer can block specific banks they already have direct relationships with, to avoid breaching the per-bank cap there).
Funds settle to the 7 partner banks via Fedwire as a single batch transfer. Each partner bank records the $250,000 as a brokered deposit on its balance sheet, FDIC-insured to the originating customer in the corporation or partnership ownership category. The originating bank holds the remaining ~$250,000 and the operational customer relationship.
The customer sees one balance ($2,000,000) and one bank name on statements. The IntraFi confirmation lists the partner banks and per-bank balances, available on demand. Daily, the allocation rebalances as customer-driven withdrawals and deposits hit the account. Settlement at each partner bank is reconciled overnight via the IntraFi central settlement infrastructure.
The fintech sweep model
Fintech business accounts (Mercury, BlueVine, Relay, Brex) wrap an IntraFi-style sweep in a fintech product. The structure is materially the same as a traditional ICS, but the originating bank is a partner bank (Choice Financial, Coastal Community Bank, Thread Bank, etc.) rather than a community bank that offers ICS to its customers directly. The fintech is the customer-facing operator; the partner bank is the originator; IntraFi (or a comparable network) operates the inter-bank allocation.
Published 2026 sweep limits on the common fintech business accounts:
Source: each fintech's partner-bank disclosure on their terms-of-service page, current as of April 2026. Verify directly with each provider before depositing large balances.
CDARS: the time-deposit version
CDARS (Certificate of Deposit Account Registry Service) is the time-deposit sister product to ICS. A customer wanting to hold $5 million in CDs places one order with their originating bank; CDARS allocates the funds across partner-bank CDs at the same advertised rate, in sub-$250,000 increments. Each CD is FDIC-insured at the partner bank.
For a business holding seasonal cash that does not need to be liquid for 90 to 365 days (a construction firm with bonding deposits, a law firm with settlement trust funds awaiting disbursement, an SaaS company between funding rounds), CDARS at 4.25 to 5.10 percent on a 6-month CD is a materially better option than the same money sitting in a 0 percent checking account, while preserving the full FDIC sweep coverage. The originating bank typically marks up the CDARS rate by 10 to 25 bps versus what each partner bank pays directly, which is the implicit fee.
CDARS is offered through over 3,000 IntraFi member banks. The originating bank for a CDARS placement is whichever community bank the business already has a relationship with. There is no fintech equivalent of CDARS at the small-business tier; it remains a traditional-bank treasury product.
What the Synapse failure exposed
On 22 April 2024, Synapse Financial Technologies filed for Chapter 11 bankruptcy. Synapse was a banking-as-a-service middleware company providing the technical infrastructure between consumer and business fintech apps (Yotta, Juno, Yieldstreet's banking product, and dozens of others) and their partner FDIC-member banks (Evolve Bank and Trust, Lineage Bank, AMG National Trust, American Bank). When Synapse failed, the ledger reconciliation between the app-side balances customers saw and the actual deposits at each partner bank was incomplete. As of the court-appointed trustee's reports through late 2024, between $65 million and $96 million of customer funds were unaccounted for, distributed across approximately 100,000 affected end-users.
The FDIC's role in the Synapse situation was limited. FDIC insurance covers deposits held at FDIC-member banks. The partner banks (Evolve, Lineage, etc.) did not fail; they continued holding the customer deposits as insured liabilities. The failure was at the middleware layer, where the per-customer attribution lived. Without functional middleware records, the partner banks could not always identify which dollars belonged to which end-customer, and the FDIC's insurance pays at the partner-bank level, not the fintech app level.
The CFPB and OCC issued joint guidance in 2024 requiring banks-as-a-service partner banks to maintain independent ledger reconciliation, not rely solely on the middleware's records. The structural lesson for business depositors: when a fintech account is layered through middleware (rather than a direct fintech-to-partner-bank arrangement), there is a non-FDIC risk that the fintech business cannot communicate clearly. For business operating cash above $250,000, prefer fintechs that have direct partner-bank relationships and use IntraFi as the sweep operator, over those running self-administered sweeps or middleware-based ledgers.
Mercury, BlueVine, Relay, and Brex do not use Synapse and were unaffected. Their architectures involve direct fintech-to-partner-bank relationships with IntraFi as the inter-bank operator. The Synapse-affected apps were primarily consumer savings products with smaller business exposure.
Sweep network pricing economics
On a traditional bank ICS arrangement, the sweep network operator (IntraFi) charges the originating bank a basis-point fee on swept balances, typically 4 to 8 bps. The originating bank charges the customer either explicitly (a flat sweep fee, typically 10 to 25 bps) or implicitly (by paying the customer a yield below the gross yield earned at partner banks, with the spread being the bank's compensation). At a 3.5 percent fed funds rate environment, a 15 bp spread on $1 million is $1,500 per year. The customer gets full FDIC sweep coverage in exchange.
On a fintech business account, the sweep is bundled with the account. Mercury Vault is free at any balance. BlueVine sweep is included with the standard account. Relay's $3M sweep is included on the free Standard tier. The implicit cost is that the fintech pays no checking APY (Mercury, Relay) or a below-market APY (BlueVine at 1.5 percent), and earns a net interest margin on the deposit through its partner-bank arrangements. Whether that is a good deal depends on the alternative: for treasury balances above $250,000 that would otherwise be uninsured, the implicit cost is much less than the cost of an uninsured failure.
The clearest mental model: a sweep network is a per-dollar insurance product priced at 5 to 25 bps annually. For balances above $250,000, that price is almost always worth paying. For balances below $250,000 at a single FDIC-member bank, the sweep is unnecessary.
How to verify a sweep is real
Three checks before depositing significant balances into a sweep arrangement:
- Read the partner-bank disclosure. It should name the originating bank (with FDIC certificate number), the network operator (IntraFi, CDARS, or named alternative), and either list partner banks or describe the rule under which they are selected. If the disclosure is vague about partner banks, ask before depositing.
- Cross-check the originating bank's FDIC membership. Use FDIC BankFind to confirm the bank is active and FDIC-insured. The FDIC certificate number on the disclosure should match.
- Ask for a per-deposit confirmation. For ICS at a traditional bank, request the per-partner-bank allocation report after a deposit. For fintechs, the partner-bank allocation should be queryable from the account interface or by support request. If the fintech cannot produce a per-partner-bank allocation, the sweep may be a marketing description rather than a real IntraFi placement.
Continue reading
Frequently Asked Questions
What is a bank sweep network?
A bank sweep network is a service that automatically distributes a customer's deposits across many FDIC-member banks in sub-$250,000 increments so that each underlying balance is fully insured. The customer sees one statement and one account balance; the network handles the per-bank allocation and reconciliation. IntraFi (formerly Promontory Interfinancial Network) is the dominant operator for both transaction accounts (ICS) and time deposits (CDARS).
Are sweep network deposits really FDIC insured?
Yes. Each partner bank holds the swept deposit as its own FDIC-insured liability, and each customer's allocation at each partner bank is insured up to $250,000 in the applicable ownership category. If a partner bank fails, the FDIC pays out the insured portion at that bank, and the customer's deposits at the other partner banks are unaffected. The originating bank's statements and the network's confirmations are the audit trail for which dollars sit at which partner bank.
Is a sweep network the same as a money market mutual fund sweep?
No. A money market mutual fund (MMMF) sweep moves cash out of an FDIC-insured deposit and into a securities product. MMMFs are not FDIC-insured. They are subject to net asset value fluctuation (the 2008 Reserve Primary Fund 'broke the buck' event) and to SEC liquidity gates under Rule 2a-7. A bank sweep network (ICS, CDARS, or fintech partner-bank programme) keeps every dollar in an FDIC-insured bank deposit. Both call themselves 'sweeps' but the deposit-protection treatment is opposite.
How much does a sweep network cost?
For traditional banks offering IntraFi ICS, the explicit fee is typically 5 to 25 basis points per year on swept balances, often disclosed as a spread between gross interest earned and net interest paid to the customer. For fintech business accounts (Mercury, BlueVine, Relay, Brex), the sweep is bundled with the account at no separate fee. The implicit cost is that the customer foregoes some interest yield versus depositing at the highest-paying partner bank directly. For balances above $250,000 where the alternative is uninsured exposure, the spread is the price of insurance.
What is the maximum FDIC coverage a sweep network can provide?
IntraFi ICS coverage is currently described as up to $277 million per customer per FDIC-member bank, because the IntraFi network has expanded to over 3,000 participating banks (3,000 banks at $250,000 each is over $750 million, but the practical placement ceiling is much lower). For business banking, the more commonly cited figures are the per-account ceilings: Mercury Vault $5M, Brex Cash $6M, BlueVine $3M, Relay $3M. These are the published programme limits, not the IntraFi limit.
Who actually runs the sweep network in a fintech account?
Most fintech business accounts use IntraFi as the underlying network operator. Mercury uses IntraFi via Choice Financial Group as the originating bank. BlueVine uses IntraFi via Coastal Community Bank. Relay uses IntraFi via Thread Bank. Brex Cash uses a multi-partner programme administered through Brex Bank and partner FDIC institutions. The partner-bank disclosure on each fintech's terms page names the originating bank and either lists the partner banks or describes the rule under which they are selected.
What happens if the fintech (not the partner bank) fails?
This is the structural risk the 2023 Synapse failure exposed. Synapse was a banking-as-a-service middleware company that sat between fintech apps and their partner banks. When Synapse entered bankruptcy in April 2024, the per-customer reconciliation between what app-side ledgers showed and what was actually on deposit at each partner bank was incomplete. The FDIC pays the partner bank's insured liabilities, but if the failed middleware's records cannot be reconstructed, individual customers may face delays or shortfalls. For business deposits at fintechs, prefer those using established sweep networks (IntraFi) over those running self-administered sweeps or relying on middleware ledgers.