For a solo owner running Profit First, the banking partner you pick comes down to one question that has nothing to do with yield or brand: does each allocation bucket become a real checking account on its own, or a sub-account hanging off one main balance?
Relay answers that better for most solo owners. Every bucket is a first-class checking account with its own account and routing number—up to 20 of them on the Starter plan at $0/month with no monthly maintenance fees—so the multi-account setup Profit First needs is the product’s default, not a workaround. Mercury is a capable banking platform with a genuine edge in yield on idle cash, but that yield lives in Mercury Treasury, which requires a $250,000 minimum and excludes sole-proprietor LLCs, which is out of reach for most solo owners.
Both platforms can automatically split incoming deposits by percentage, so that part isn’t the tiebreaker people assume it is. What separates them is how each one treats those accounts, and who each one was built to serve.
Where Relay wins for the solo owner
Relay treats every bucket as a first-class checking account. Open one for Income, Profit, Owner’s Pay, Tax, and Operating Expenses, and each gets its own account number—up to 20 on Starter and Grow, and up to 50 on Scale. You’re not nesting envelopes under a primary checking account; the buckets are the structure.
Beyond the count, the everyday details favor Relay too:
Savings on every plan. Relay includes savings accounts at every tier, with no minimum balance to open one—so tax and profit reserves don’t have to sit in checking.
Cash deposits. If you take any cash, Relay supports deposits at Allpoint ATMs and through the Green Dot Network. Mercury accepts no cash at all.
Clean books. QuickBooks Online and Xero sync on every plan, so your accountant sees the same account structure you do.
A solo owner can run a full Profit First setup on Relay’s Starter plan at $0/month, with no monthly maintenance fees and no minimum balance, then move up to Grow or Scale only when team size or transaction volume actually calls for it.
Where Mercury wins for the solo owner
Mercury is the stronger choice if you’re a funded startup sitting on cash you won’t touch for months. Its standout feature is Mercury Treasury, which can move idle balances into money market or short-bond funds yielding around 3% (which is real money if you’re holding $250,000 or more). Below that minimum, Treasury isn’t available, and it excludes sole-proprietor LLCs entirely, so the typical solo owner never reaches it. It’s also an investment product protected by SIPC, not FDIC deposit insurance.
Mercury also runs lean on transaction fees: free domestic and international USD wires and free same-day ACH, where Relay charges for those on most plans and includes same-day ACH only on Scale. For a high-volume payer, that adds up. Mercury spreads deposits across more partner banks for a higher insurance ceiling too—up to $5 million, versus Relay’s up to $3 million through Thread Bank’s sweep program²—which starts to matter once balances climb past what one bank can cover. And its brand maturity is real: more than 300,000 customers and a reputation built in the startup world.
²Your deposits qualify for up to $3,000,000 in FDIC insurance coverage when Thread Bank places them at program banks in its deposit sweep program. Your deposits at each program bank become eligible for FDIC insurance up to $250,000, inclusive of any other deposits you may already hold at the bank in the same ownership capacity. You can access the terms and conditions of the sweep program at https://thread.bank/sweep-disclosure/ and a list of program banks at https://thread.bank/program-banks/. Please contact customerservice@thread.bank with questions on the sweep program. Certain conditions must be satisfied for pass-through deposit insurance coverage to apply.
How each one handles your Profit First buckets
Profit First splits every deposit across dedicated accounts on a set rhythm, so the money for taxes and profit is separated before you can spend it. Both Relay and Mercury automate that split with percentage-based rules that fire when a deposit lands, so allocation itself is a tie.
What differs is the buckets. On Relay, each bucket is a standalone checking account with its own number—the exact model Profit First assumes. On Mercury, the experience centers one primary checking account with sub-accounts underneath it; you can build the same buckets, but you’re working against the product’s default instead of with it. For a solo owner who opens the app expecting to see five funded accounts side by side, that default shapes the daily experience.
What each one costs to run as a solo owner
Both platforms start at $0/month with no monthly maintenance fees, so the price of entry is the same. The paid tiers buy different things. Relay’s Grow ($30/month) and Scale ($120/month) add accounts and capacity as you grow. Mercury’s Plus ($29.90/month) and Pro ($299/month) add invoicing and expense-workflow features, not more accounts or any yield—core banking is identical at every Mercury tier.
On the attributes that decide it for a solo owner:
Attribute | Relay | Mercury |
|---|---|---|
Built for | Solo owners organizing cash by purpose | Venture-backed startups managing idle cash |
Monthly subscription fees | Starter $0/mo, Grow $30/mo, Scale $120/mo | $0; Plus $29.90/mo; Pro $299/mo |
Checking accounts | Up to 20 (Starter/Grow), up to 50 (Scale) | Not publicly stated |
Savings Annual Percentage Yield (APY) | Starter 1.11%, Grow 1.75%, Scale 3.00% APY¹ | None on checking; Treasury yield, $250K min |
Automated cash allocation | Yes, percentage- or dollar-based auto-transfers, all plans | Yes |
Cash deposits | Supported at Allpoint ATMs and via the Green Dot Network | — |
¹For Relay Subscription Plans with an interest-bearing deposit account, the interest rate and Annual Percentage Yield on your account are accurate as of 5/1/2026 and are variable and subject to change based on the target range of the Federal Funds rate. Fees may reduce earnings: When you are subscribed to the Starter Plan, the interest rate on your savings accounts is 1.10% with an APY of 1.11%. When you are subscribed to the Grow Plan, the interest rate on your savings accounts is 1.74% with an APY of 1.75%. When you are subscribed to the Scale Plan, the interest rate on your savings accounts is 2.96% with an APY of 3.00%.
Note: Mercury does not publish a checking-account limit, and its Treasury yield requires a $250,000 minimum across accounts and excludes sole-proprietor LLCs.
How to choose between Relay and Mercury
Pick Relay if you’re a solo owner who organizes cash by purpose and wants each Profit First bucket to be its own funded account from day one—especially if you’re a sole proprietor or single-member LLC, you take cash, or you just want the multi-account view as your default.
Pick Mercury if you’re a funded startup holding $250,000 or more in idle cash you want earning yield, you send frequent wires, or you want the deposit-insurance ceiling and brand that come with a larger institution.
For most solo owners running Profit First, the deciding factor isn’t yield they’ll never access or a brand name—it’s whether the buckets are real accounts that fund themselves. Relay fits the method without a workaround.
If you’re setting up Profit First as a solo owner, opening a Relay account gives you the structure out of the box: up to 20 checking accounts with no monthly maintenance fees, automated percentage-based transfers that move tax and profit reserves on every deposit, savings accounts on every plan, and QuickBooks Online and Xero sync to keep your books clean.
Frequently asked questions
Can a sole proprietor open a Mercury account?
Mercury is built around U.S.-registered companies with an EIN, and its Treasury product explicitly excludes sole-proprietor LLCs. If you operate as a sole proprietor, confirm current eligibility with Mercury directly before applying. Relay, by contrast, is built for small businesses broadly, including single-member LLCs and solo owners organizing cash by purpose.
Does Mercury support Profit First the way Relay does?
Both platforms let you create multiple accounts and automate percentage-based transfers on incoming deposits, so the mechanics of Profit First work on either one. The difference is structure: Relay makes each bucket a standalone checking account by default, while Mercury organizes sub-accounts under a single primary checking account.
Is Relay or Mercury better for a solo owner who wants to earn on reserves?
For a solo owner with typical balances, Relay is better—its savings accounts are available on every plan with no minimum to qualify. Mercury’s yield comes only through Mercury Treasury, which requires a $250,000 minimum and excludes sole-proprietor LLCs, so most solo owners can’t reach it.
How many accounts can I open with Relay?
Relay offers up to 20 checking accounts on the Starter and Grow plans and up to 50 on Scale, plus up to two savings accounts. That covers a full Profit First setup—Income, Profit, Owner’s Pay, Tax, and Operating Expenses—with room left over for additional reserves like equipment or payroll.
