How should a US startup avoid having all its cash at one bank?

A practical setup is to separate operating cash from reserves and diversify both institutions and access:

1. Keep day-to-day cash at your primary bank. Hold enough for payroll, vendors, and near-term obligations—but not necessarily the whole runway.
2. Open a backup account at a separately chartered bank. Keep enough there to run payroll and critical payments if your primary bank or its payment systems are temporarily unavailable. Different brands can share the same bank charter, so verify they’re genuinely separate institutions.
3. Move excess cash into a reserve strategy. Options include:
   • FDIC-insured deposits at multiple banks. The standard limit is $250,000 per depositor, per insured bank, per ownership category. A corporation’s accounts in the same category at the same bank are generally aggregated—not insured separately just because they’re different account types. (fdic.gov)
   • A bank deposit-sweep network. Ask how funds are allocated, which banks receive them, how existing deposits affect coverage, and how quickly you can get the money back. Confirm the pass-through insurance and recordkeeping arrangements in writing; coverage depends on requirements being met. (fdic.gov)
   • Short-term U.S. Treasury bills, held in the company’s name through an appropriate Treasury or brokerage account. They aren’t FDIC-insured deposits, but are backed by the U.S. government; match maturities to when you expect to need the cash. (fdic.gov)
   • A government money-market mutual fund, if appropriate for your liquidity needs. It is an investment—not an FDIC-insured bank deposit—and can carry risk. (investor.gov)

Operational safeguards matter too: keep account access and payment credentials separate, set up backup approvers, test transfers, and document who can move money. Don’t leave all liquidity in a product that takes days to redeem or settle.

A simple starting point: primary bank for operations, separate backup bank for immediate continuity, and a diversified reserve for cash you don’t need right away. Have your CFO or accountant model cash needs and review the account ownership, insurance, and tax treatment before moving funds.

You have three main options: spread the money across banks yourself, use a sweep network, or hold some cash in government-backed instruments. Your cash can be fully insured without you ever holding more than the limit at any single bank.

1. Open accounts at several banks
The basic rule is that the FDIC insures deposits up to $250,000 per depositor, per insured bank, per ownership category. Keeping each bank's balance under that line works, but different branches of the same bank are still the same bank, and so are its online and mobile divisions. For a company holding roughly $500,000 to $750,000, two or three banking relationships solve the problem completely. The downside is operational. Businesses that try to stretch this approach past four or five banks usually end up with idle cash stranded in the wrong place. Also, business owners should account for the accumulation of anticipated interest earnings and keep track of incoming and outgoing funds, since those can push a balance over the limit without warning.

2. Use a sweep network through one bank
Insured cash sweep programs let you keep a single banking relationship while your money is placed elsewhere. You deposit, manage and withdraw funds from one primary business bank account, while sweep accounts spread funds across a network of FDIC-insured banks, placing up to $250,000 at each. The main networks are IntraFi's ICS and CDARS. Customer funds are placed into demand deposit accounts and money market deposit accounts with ICS and in CDs with CDARS. Several fintech banks offer this to startups. For example, Rho's business savings account offers up to $75 million in FDIC insurance coverage. Mercury and Brex advertise about $5 million and $6 million, respectively. Check the current limit and terms directly with any provider, because these figures change. Also, the business savings account provides up to $75 million in ICS coverage but doesn't pay interest. So compare the yield against the coverage.

3. Put part of the reserve in non-deposit instruments
FDIC coverage is not the only tool. Businesses with large cash balances should also consider money market funds, T-bills, and CDs, though each has different liquidity, maturity, and risk profiles. Treasury-backed funds and bills are not FDIC-insured deposits, so they are a different kind of protection and should be evaluated on their own terms.

Practical steps

• Work out how much you need to keep liquid. Many businesses target 12–16 months of operating expenses in liquid accounts.
• Decide how much sits in operating accounts (for payroll and bills) versus reserves (which can be in a sweep or Treasury product).
• Check each bank's exposure, including any sweep partners, so you don't double-count the same bank.
• Confirm the setup with your accountant or a banking advisor, especially if you have several entities or investors who want specific protections.

To avoid the risks associated with holding all cash in one bank, startups should move beyond traditional, single-account banking and adopt a structured treasury management strategy.

The goal is to balance liquidity, safety (insurance), and yield. Below are the most effective ways to diversify your cash holdings.

1. Utilize Insured Cash Sweeps (ICS)

For many startups, this is the most efficient way to manage large balances without the administrative burden of opening dozens of bank accounts.

• How it works: Many fintech-forward banks and platforms offer "sweep" products that automatically distribute your deposits across a network of multiple FDIC-insured banks.
• Benefit: This keeps your funds within the FDIC insurance limits (typically $250,000 per bank) while still providing you with a single point of contact and a unified dashboard.

2. Implement a Tiered Cash Strategy

Do not keep all your cash in a single, idle checking account. Instead, categorize your funds by liquidity needs:

• Operating Tier (0–30 days): Keep enough cash in your primary, highly liquid checking account to cover 4–6 weeks of payroll and critical vendor payments.
• Reserve Tier (30–90 days): Move excess cash into low-risk, interest-bearing vehicles like government money market funds. While these may not be FDIC-insured, they are generally considered very safe and offer better yield.
• Strategic Tier (3+ months): For long-term reserves, consider U.S. Treasury bills (T-Bills). These are held in investment accounts and are separate from bank deposit risks; even if your bank fails, your T-Bills remain secure.

3. Maintain Multiple Banking Relationships

If your company has significant cash balances, relying on a single institution creates "concentration risk".

• Diversify partners: Establish relationships with at least two or three different banks.
• Operational separation: Use different banks for specific functions. For example, keep your main operating account at a large, global systemically important bank (G-SIB) for stability, while using a secondary, more specialized bank for payroll or day-to-day operational needs.

4. Best Practices for Execution

• Conduct Due Diligence: When choosing a bank, look beyond features. Review their financial stability, asset base, and whether their business is overly concentrated in a single, volatile industry (like tech or crypto).
• Automate, Don't Manualize: Managing multiple accounts manually is error-prone and time-consuming. Use treasury management software or bank-integrated tools that provide real-time visibility into your total cash position across all accounts.
• Establish a Treasury Policy: Even early-stage startups should have a written policy that defines:
  • Maximum allowable exposure to any single bank.
  • Requirements for FDIC insurance.
  • Authorized investment vehicles (e.g., T-Bills vs. corporate bonds).

Disclaimer: I am an AI, not a financial advisor. Cash management strategies should be tailored to your specific burn rate, growth stage, and risk tolerance. Consult with your CFO, accountant, or legal counsel when establishing your company’s treasury policy.

A U.S. startup should manage cash by purpose, access needs, and risk—not simply by opening more accounts.

• Keep operating cash at more than one bank. Maintain a primary account for payroll and payments, plus a separate account at another bank that can cover near-term expenses if the primary bank or its systems are unavailable. Avoid making the backup account dependent on the same banking provider or platform.
• Know the insurance limit. A corporation or LLC’s deposits at one FDIC-insured bank are generally combined and insured up to $250,000. Multiple accounts or trade names at the same bank don’t multiply that limit. Confirm the legal account owner and the bank’s FDIC status. ¹
• For balances above the limit, choose a deliberate structure. Options include spreading deposits across separate insured banks, or using a deposit-placement service that distributes funds among participating banks. With a sweep or placement service, check which banks actually hold the money, how balances are tracked, fees and withdrawal timing, and whether the arrangement satisfies FDIC pass-through requirements. Pass-through coverage isn’t automatic and the funds still count toward the company’s other deposits at each receiving bank. ¹²
• Consider Treasury bills for cash you don’t need immediately. They’re not bank deposits, so FDIC insurance doesn’t apply; match maturities to expected cash needs and consider operational and market risks.
• Don’t treat a money market fund as an insured bank account. It may be a useful cash-management investment, but it is not FDIC-insured and is distinct from a bank money market deposit account. ³
• Write a short treasury policy. Set a minimum operating balance, maximum exposure per bank or provider, permitted investments and maturities, who can move funds, and how often balances and counterparties are reviewed. Keep credentials and approval authority separate enough that one incident or unavailable person doesn’t block payroll.
• Test the backup. Verify that a second authorized person can access the alternate account, that payment instructions work, and that funds can be moved when needed.

For a startup with substantial runway or investor funds, have its CPA, treasury adviser, or counsel review the setup—especially sweep arrangements and how the company’s legal entity is titled on accounts.

¹ FDIC: Are My Deposit Accounts Insured? ² FDIC: Pass-through Deposit Insurance Coverage ³ SEC: Investor Bulletin—Money Market Funds