Cash Management for Founders in 2026: Treasury Yields, Real Fees, and Where Your Money Should Sit
Most founders don’t think about their business account for more than five minutes a year. You pick one, you move money in, you pay people, you move on. That’s the whole job.
That worked fine in 2019. It doesn’t work now, because the interesting part of your cash pile is not sitting in a checking account doing nothing. Rates have moved enough that idle money has a real price, and the gap between a good setup and a lazy one is thousands of dollars a year on a moderate balance.
Here’s the thing that trips people up. Treasury, where your idle cash earns yield, is not a feature of your checking account. It’s a separate product, usually a separate legal wrapper, usually a different set of rules about how fast you can get the money back. Founders compare banks on monthly fees and card rewards, then leave hundreds of thousands of dollars earning nothing because they never went looking for the second account.
This guide covers what the money layer actually costs in 2026, which platforms are worth the switch, and where the gotchas are that the marketing pages skip.
The two decisions founders keep confusing
Break “banking” into two separate purchases and the whole thing gets much clearer.
The first is where the money lives: your operating account, the one that funds payroll and vendors. The second is how you control what gets spent: cards, approval rules, expense workflows, accounting sync.
These used to be one product. They aren’t anymore, and most of the confusion in this category comes from buying a spend tool when you needed a cash tool, or the other way around.
For a solo founder with no employees and under $100K in the bank, you need neither a fancy spend platform nor a treasury account. A free checking account with free ACH is genuinely enough. That’s the honest answer for most people reading this.
The interesting decisions start when you have real money sitting around. Two hundred thousand dollars in a 0% checking account is a mistake that costs you roughly $8,000 a year at current short-term rates. That gap is worth an afternoon of setup.
Mercury: the default, and what it actually costs
Mercury is the most common answer for a reason. It handles the boring layer well, the money layer is free, and the fee structure is simple enough to explain in a sentence.
Here’s the current breakdown. The base plan is $0 a month with no minimum balance. You get free ACH, free domestic wires, free USD international wires sent as SHA, real-time payments, checks, debit cards, bill pay, invoicing, and QuickBooks and Xero sync. Reimbursements are included for up to five active users per month, which means if you need a bigger team reimbursing out of pocket, you are on a paid plan.
Then there are the two paid tiers, and they are not cheaper banking. Mercury Plus runs $35 a month, or $29.90 billed annually, and adds recurring invoices, ACH debit on invoices at $1 a transaction, unlimited 1099 filings, six months of Xero free, and $50 off eligible LegalZoom compliance plans. Mercury Pro is $350 a month, or $299 annually, and adds a relationship manager, ACH debit at $0 per transaction, NetSuite categorizations, and unlimited 1099s.
Mercury advertises 1.5% cashback on its IO card, subject to eligibility and terms. The card is issued by Patriot Bank and is cash-underwritten, so your balance can’t exceed your Mercury cash, and there’s a daily repayment mechanic up to a $15,000 total Mercury balance, then monthly. Flat rate is what you want early, before you know what your spend categories actually look like.
Where the real cost hides is foreign exchange and treasury fees. Non-USD outgoing wires carry a 1% currency exchange fee, negotiable above $200K a month. Non-USD card transactions carry a 3% exchange fee, it applies to non-USD ATM withdrawals, and it is not refunded and excluded from cashback. That’s steep if you have contractors or customers billing in euros.
On the cash side, Mercury Treasury quotes up to 4.21% yield using Mercury-exclusive funds and U.S. Treasury ladders, and it unlocks with a $250,000 Mercury balance. The fee is 0.15% to 0.60% depending on balance, and that fee comes out of the yield Mercury quotes. If you’re comparing platforms on headline yield, remember that a 4.21% figure with a 0.60% fee is a 3.61% figure, and Mercury’s fee scales with balance so the effective rate moves as you grow.
The cash yield picture, and what “up to” hides
Here’s where I think most comparisons get sloppy. Every platform advertises a yield. Almost none of them guarantee it, and the gap between the headline number and what you actually collect can be large.
Mercury quotes up to 4.21% on a portfolio of its own funds and Treasury ladders, with a $250K balance threshold to unlock and a 0.15% to 0.60% fee.
Bluevine’s headline yield is tied to its plan. Standard pays 1.3% APY, Premier pays 3.3%, and either way interest accrues only on the first $250,000 of your balance. The Premier plan runs about $95 a month. So the 3.3% number only exists if you pay roughly $1,140 a year, and it stops paying at $250K.
Slash offers treasury with no minimum balance, and its paid tier runs $0 or $25 a month per entity with no per-user fees. Its checking deposits are eligible for up to $150M in FDIC insurance through Column N.A.’s insured cash sweep network.
Rho charges $0 for banking, but the catch is in Rho Treasury, and it’s a real catch. Rho’s own disclosure says Treasury is a securities investment account, not an FDIC-insured deposit. It lists several holdings, and it says VFSTX and VFSUX are closed to new investments. An advertised return on a securities account is not a guaranteed deposit yield, and you need to check your actual allocation, redemption horizon, and principal risk before you trust it.
Relay is the multi-account play. It advertises up to 20 business checking accounts, which is useful for reserves, envelope-style cash management, or separating business lines. Its card rewards are tiered: Starter earns 1%, and the 1.5% rate requires the $120 a month Scale plan.
Ramp’s advertised “up to 1.5%” is a variable rate set per business, with a real range of 0% to 1.5%. You may not learn your company’s actual rate until after you’ve signed. Ramp also requires a $25,000 minimum balance to open.
Brex is the one most founders will land on eventually, and it is a later-stage tool. Its points table includes 7x rideshare, 4x eligible Brex Travel, and 3x restaurants for one applicable program, with other tiers differing. Everything outside the bonus categories earns 1x. Brex requires $50,000 in a business account to open, and it bundles expense management and travel booking that you don’t need when it’s two cofounders and a $500K runway.
The math on idle cash, which is the actual reason to bother
Let’s make this concrete, because “optimize your treasury” is the kind of advice that sounds smart and gets ignored.
At $50,000 in cash, the difference between 0% and 4% is $2,000 a year. At $250,000 it’s $10,000. At $1 million it’s $40,000.
Now subtract the fees. Bluevine Premier at $95 a month costs $1,140 a year, which eats more than half of the yield on a $50,000 balance at 3.3%, which is $1,650. At that balance the Premier tier costs more than it pays.
Mercury’s fee of 0.15% to 0.60% on $250,000 is $375 to $1,500 a year. On a 4.21% headline, $250,000 earns $10,525 before fees, so you’re looking at roughly $9,025 to $10,150 depending on which fee tier you land in.
The clean rule that falls out of this: the higher your balance, the more the fee tier matters, and the lower your balance, the more the monthly subscription matters. Below about $100K, a flat 0% monthly fee with a percentage-based treasury fee beats any subscription tier. Above roughly $300K, a subscription with a low APY cap and a high balance limit starts to win because the flat fee is a rounding error against the yield.
Eligibility is the filter nobody reads
All of these platforms have eligibility requirements, and they are the reason a founder who read the whole comparison still gets rejected.
Mercury requires a U.S.-incorporated company, and for non-US founders it has its own founding structure. Its Treasury needs a $250K balance. Ramp needs $25,000 minimum. Brex needs $50,000.
That means for a founder with $30,000 in the bank, Brex and Ramp are simply off the table, and the real choice is Mercury, Relay, Bluevine Standard, or Slash depending on whether you want multi-account structure, accounting integrations, or nothing in particular.
Mercury is also not a bank. It’s a financial technology company. Choice Financial Group and Column N.A., Members FDIC, provide the accounts. Relay and Bluevine have their partner banks. Ramp runs through a partner as well. This is normal and it’s not a problem, but it matters when you’re deciding whether a balance is FDIC-insured, SIPC-covered, or held in a securities account. Those are three different things and the marketing pages rarely distinguish them clearly.
Where founders actually get burned
Three failure modes show up repeatedly.
The first is the securities account treated as a deposit. Rho’s disclosure is explicit that Treasury is a securities investment account, not an FDIC-insured deposit, with some funds closed to new investments. If your cash is in a securities wrapper and you need it in 30 days, you need to know the redemption timeline before you need it. Read the actual account and product agreements, not the comparison table.
The second is the yield that isn’t yours. Ramp’s 0% to 1.5% range means your rate is set for your business, and you find out after signing. Mercury’s fee comes out of the quoted yield. Bluevine caps interest at $250,000. Every one of these is a small print item that changes the math.
The third is compliance friction freezing access. Some founders described restrictions after unanswered compliance requests. That’s anecdotes, not a platform-wide rate, but the operational lesson is real: assign an owner to bank requests and keep a backup liquidity plan. This matters more than most people expect, because the moment your account freezes, payroll is at risk and switching banks mid-month is genuinely painful.
The setup I’d actually run
Here’s what I would do with a US-incorporated company, roughly $150,000 in the bank, and no employees yet.
Open a free operating account. Mercury at $0 covers free ACH, free domestic wires, and accounting sync, and the $35 Plus tier isn’t worth it until you’re actually reimbursing more than five people or need unlimited 1099s.
Park the idle cash in Treasury with a sweep rule that moves anything above your next 90 days of expenses into the yield account automatically. Don’t try to time it manually. The whole point is to remove the decision.
Hold a separate operating reserve so you can always cover payroll. Two accounts, one institution, no manual transfers between them.
Set the FX threshold before you need it. If more than 10% of your spend is non-USD, the 3% card fee is a real problem and you should be negotiating a rate with your provider or routing through a different bank. Don’t discover this on your first EUR invoice.
Recheck the whole thing every time you close a round or cross a balance threshold. Rates move, fee tiers move, and a platform that was wrong at $50K can be right at $500K.
When you’re ready to move up
Three signals mean you’ve outgrown the free tier.
You’ve hired beyond ten people, or travel spend is climbing. That’s when Brex’s approval rules and Brex Travel start paying for themselves, and a $50,000 minimum stops being a barrier because you’re past it anyway.
Your bookkeeping is taking more than a few hours a month. Ramp and Brex both do expense reconciliation better than a $0 plan, and the savings show up in the accountant’s bill.
You need to hold operating cash and investment cash separately for board reporting or an audit. Relay’s 20-account structure is built for this, and separate checking accounts are a clean way to show the separation, though they don’t create legal entity separation on their own. Confirm the entity structure and accounting treatment before you rely on it.
Bottom line
If you have under $100K and no employees, the free tier is the right answer and everything else is a distraction. If you have $250K or more sitting in a checking account earning nothing, the switch to a cash management product is one of the highest-return hours you can spend on your business this quarter. The math is simple and the setup is an afternoon.
Just read the fee schedule rather than the headline, and know whether your cash is sitting in a deposit account or a securities account before you make a plan that depends on getting it back on short notice.
