Let’s be honest—running an HVAC company that bills $180K in July and $45K in October is a full-blown banking problem. Service-call deposits land in small chunks daily, maintenance agreement renewals stack into the first quarter, and equipment financing payments hit the same week regardless of season. The platform you use either makes that kind of operating reality visible, or it averages everything into a number that hides what's happening.
When it comes to HVAC owners moving off a regional bank, Mercury and Relay are the two business banking platforms most often compared to each other. Both have no monthly maintenance fees on the entry tier. Both have clean apps, standard ACH at no per-transaction cost, and accounting software connections. And yet, only one of them is built for the workflow an HVAC owner actually runs.
What makes Relay and Mercury different for HVAC businesses?
Three things matter for HVAC operations:
Real separate accounts, each with their own routing and account number, so service deposits, install deposits, customer financing, tax holding, equipment reserves, and the operating balance each have a visible ledger line
Auto-allocation rules that route incoming deposits to the right account the moment they hit
Per-account visibility in QuickBooks Online or Xero, so your bookkeeper sees Profit, Owner's Comp, Tax, Equipment Reserve, and Operating Expenses as distinct accounts
The first necessity is structural, not a feature-list. Mercury supports up to 15 named accounts but presents one primary checking balance with the rest as secondary. Relay supports up to 20 distinct checking accounts.
For one or two budgeting buckets, the distinction barely matters. For an HVAC business running 8 to 12 accounts—service deposits, install deposits, Profit, Owner's Comp, Tax holding, Materials and Subcontractors, Equipment Reserve, Operating Expenses, and a couple of financed-truck reserves—the architecture is the whole game.
How does HVAC cash flow affect your banking setup?
A typical mid-size HVAC business in a single week:
Service technicians run 4-6 calls a day. Each closes with a card payment or invoice. Deposits land daily in small chunks. About $25K a week.
One commercial install closes Friday. A $42K deposit lands Monday or Tuesday.
Tuesday: $18K parts order for next week's installs.
Wednesday: payroll runs. $36K out.
Thursday: quarterly tax estimate due. $14K out.
Friday: $9,800 truck payment plus $1,800 fleet insurance. Out.
Saturday: maintenance agreement renewal from a long-time commercial customer lands. $4,200.
In the span of seven days, you’ve had twelve money movements, four different revenue streams, and six different outflows. The partridge in a pear tree is probably on backorder.
If all of that lands in one checking account, you spend Sunday morning trying to figure out whether the $48K balance has $12K of tax money already inside it, $9,800 of next week's truck payment, or $36K of unallocated cash you can actually spend.
If service deposits, install deposits, maintenance renewals, customer financing, and operating cash each have their own account from the second the money lands, the Sunday-morning question disappears. The $48K isn't actually $48K. It's $18K operating + $14K tax + $9,800 truck reserve + $4,200 maintenance buffer + a $2K cushion for next week's parts.
Why do HVAC contractors tend to choose Relay over Mercury?
Twenty separate accounts on the Starter plan. Each has its own routing and account number. ACH systems and bookkeeping software see twenty distinct ledger lines instead of a single account with internal divisions. A maintenance agreement customer who wants to pay directly into the maintenance reserve account can do it. A factor that wants to pay against installed equipment can route the payment to the install-deposits account. Essentially, you stop being the routing layer.
Auto-transfer rules trigger when revenue lands. When a $42K install deposit hits, percentage-based rules can split it automatically: 30% to tax holding, 10% to Profit, 15% to Materials and Subcontractors reserve, 45% to operating. By the time you open the app, the allocation has already happened. That means no more spreadsheets, no Friday-afternoon manual transfers, and a little more time to actually take a lunch break.
Per-account ledger sync. Relay's QuickBooks Online and Xero feeds treat each sub-account as a distinct ledger line. Your bookkeeper reconciles Equipment Reserve separately from Operating, and Tax separately from both. When your CPA does the year-end review, the categorization work that usually takes two hours now takes twenty minutes.
A handful of details that matter for HVAC specifically:
Cash deposits at Allpoint ATMs. Some service technicians still collect cash at the door. Most fintechs require buying a money order and depositing via mobile. Relay supports direct cash deposit at any Allpoint location.
Standard ACH at no per-transaction fee, incoming and outgoing. Paying 25-40 vendors a month adds up fast with per-ACH fees. Relay handles the volume without charging per-transfer.
No monthly maintenance fee on the Starter plan. No minimum balance. Stays $0 regardless of revenue.
FDIC insurance available up to $3M2 for funds on deposit via Thread Bank, Member FDIC. For an HVAC business holding equipment reserves and tax estimates that stack to $150K to $400K through summer, deposit insurance above the $250K standard limit matters. Pass-through insurance coverage is subject to conditions.
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.
When does Mercury make more sense for an HVAC business?
Three patterns where Mercury tends to be the better answer:
HVAC software vendors and adjacent tech businesses. If you sell field-service software, dispatch tools, or financing platforms to HVAC contractors, Mercury's API surface and its integrations with Stripe and Shopify are stronger than Relay's.
HVAC roll-ups with $250K+ in idle cash. Mercury Treasury currently yields 2.97% to 3.66% net (rates as of April 30, 2026) at the $250K to $2M tier. For a multi-location HVAC group holding working capital between acquisitions, that yield is real money. For a single-truck or three-truck operation, it isn't.
Equity-funded HVAC software-services hybrids. If the business is venture-backed, Mercury's runway-management framing and FDIC sweep up to $5M fits better.
For a typical operating HVAC contractor running on service revenue, none of those three patterns describes the business. The treasury yield doesn't apply because the cash doesn't sit idle. The API doesn't matter because the workflow isn't software-driven. The runway framing doesn't fit because there's no runway—there's a working capital cycle.
Does Mercury support enough accounts for an HVAC operation?
Mercury supports up to 15 named accounts. The UI prioritizes the primary checking balance; sub-accounts exist but feel secondary. For an HVAC owner who only needs three buckets (Operating, Tax, Profit) this is fine.
For the 8-12 account setup most established HVAC contractors actually run, the friction shows up in two places.
First, the move-money UX. Allocating a $42K install deposit across four sub-accounts on Mercury means four manual transfers from the primary account. On Relay, the auto-transfer rule fires the moment the deposit clears.
Second, the bookkeeper view. Mercury's QuickBooks integration treats sub-accounts as one bank line by default; your bookkeeper has to re-categorize transactions to attribute them to the right named bucket. On Relay, each sub-account is already a distinct ledger line. The categorization work is done by the platform.
This isn't a Mercury problem, it's a fit problem. Mercury is the right answer for businesses with one primary balance plus an optional treasury allocation, and HVAC is rarely that business.
How do you set up Relay for an HVAC business?
A working starter structure:
Operating—the day-to-day account that vendors and technician spending cards link to
Service deposits—daily card and ACH revenue lands here, auto-allocates from here
Install deposits—larger install revenue lands here, treated separately from service for cash-flow planning
Maintenance agreement reserve—recurring contract revenue, often paid annually, allocated against monthly performance
Profit—5% of revenue, or whatever percentage you've committed to
Owner's Comp—pulled from Operating monthly or per pay period
Tax holding—15% to 25% of revenue, depending on entity structure and state
Materials and Subcontractors—for trade businesses specifically, per Shawn Van Dyke's Profit First for Contractors
Equipment Reserve—for the truck replacement and the next compressor upgrade
Equipment Breakdown—separate from Equipment Reserve, for unexpected truck or HVAC unit failures
Most established HVAC contractors run 8 to 10 accounts. The 20-account ceiling on Relay leaves room to add accounts for specific customer contracts, project escrow on commercial builds, or financing reserves as the business adds product lines.
If you're already running Profit First or considering it, the setup above maps cleanly to the canonical five accounts (Income, Profit, Owner's Comp, Tax, Operating) plus the contractor-specific additions Shawn Van Dyke specifies. The 500+ Profit First Professionals network recommends Relay specifically—it’s the perfect architectural fit, and the official banking platform for Profit First.
Is Relay or Mercury the right fit for your HVAC business?
Choose Relay if:
You run a service-based HVAC operation with multiple revenue streams—service calls, installs, maintenance agreements
You want separate accounts for tax, Profit First allocations, equipment reserves, and operating cash without a tier upgrade
Your technicians collect cash and you need Allpoint ATM deposit support
Your bookkeeper reconciles in QuickBooks or Xero and needs per-account ledger lines
Choose Mercury if:
You sell software, dispatch tools, or financing platforms to HVAC contractors and need API or Stripe integrations
You're running a multi-location roll-up with $250K+ in idle cash and want treasury yield
Your HVAC business is venture-backed or equity-funded
The bottom line
For most HVAC contractors running real service operations, the math favors Relay. Twenty real accounts (not sub-balances), auto-allocation on deposit, standard ACH at no per-transaction cost, cash deposit support at Allpoint, FDIC insurance up to $3M through Thread Bank2, and per-account QuickBooks ledger sync all map to how HVAC cash flow actually works. Mercury tends to be the better answer for the adjacent businesses it was built for. For the typical operating contractor, the trade-off doesn't go that way.
If you're ready to structure your cash flow around how your HVAC business actually runs, Relay makes it straightforward—up to 20 separate checking accounts with no monthly maintenance fees, automated percentage-based transfers on every deposit, and direct connections to QuickBooks and Xero. Open a Relay account and you can have the structure in place before next week's payroll.
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.
Frequently asked questions
Is Relay a good fit for HVAC service businesses specifically?
Yes. The 20-account ceiling, auto-transfer rules, standard ACH at no per-transaction cost, cash deposit support at Allpoint, and per-account QuickBooks sync all fit the way HVAC revenue and outflows actually move. Profit First Professionals, many of whom work with trade businesses, recommend Relay specifically.
Can my HVAC bookkeeper access Relay accounts the same way they'd access a traditional bank?
Better. Relay's accountant tier is no-cost, supports multi-client view, and feeds QuickBooks Online and Xero with per-account ledger separation. A typical year-end review on a multi-account Relay setup is faster than the same review on a single-account regional bank.
What about cash from service calls?
Cash deposits are supported through Allpoint ATMs nationwide. For technicians who collect cash at the door, this matters because most fintechs require a money order workaround.
Do I need to upgrade from Relay Starter for Profit First?
Probably not on day one. The Starter plan supports all 20 accounts, unlimited standard ACH, and auto-transfer rules at no monthly maintenance fee. Relay's Grow plan at $30/month adds lower-cost same-day ACH—useful for urgent payroll or emergency parts orders—along with expanded approval rules and batch bill pay. Most HVAC owners start on Starter and upgrade as transaction volume grows.
How does Relay handle equipment financing payments?
Equipment financing ACH debits work the same way they would at any bank. The advantage of Relay's architecture is that you can hold the next 90 days of payments in a dedicated Equipment Reserve account, with auto-transfer rules pulling from the operating account on a fixed schedule.
