Accounting 4 Trades (ACC4T) - Financial Back Office for the Skilled Trades.

Bookkeeping for HVAC Contractors in Metro Detroit

Q: Do HVAC contractors charge sales tax on installs in Michigan?

Usually not - on an install you pay the tax when you buy the equipment, as the consumer. However, if you're selling just parts to customers, those are taxed differently.

Q: What's in the free audit?

It's typically a live call where we review pain points and any open questions you have, then dive into your QuickBooks and field service software via screenshare to highlight the top-level issues we see every day. No obligation to continue.

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Sound Familiar?

You didn't start an HVAC company to spend Sunday night matching bank deposits to invoices. But here you are... trucks to keep moving, techs to pay, a furnace-season rush bearing down, and a set of books that can't tell you whether last month actually made money. This page lays out how HVAC bookkeeping works in Metro Detroit: the local rules that trip people up, what it should cost you, and what your numbers should be telling you.

Most owners don't go looking for a bookkeeper because the books are a little messy. It's because the books stopped answering questions:

You can't say what a given install job actually netted after labor, materials, and the callback you ate.
The phones ring and the trucks are out, but the bank balance doesn't reflect it and you can't explain the gap.
Tax season is a scramble because the books aren't ready and your CPA is asking questions you can't answer.
You want to add a truck or a tech, but you're guessing on whether the business can carry it.

None of that means you're bad at running an HVAC company. It means the numbers aren't getting the attention the field work gets. The rest of this page is about what changes when they do.

Trades-only and Local

Accounting 4 Trades is a trades-only bookkeeping and CFO firm. We do the numbers behind HVAC, electrical, and plumbing companies running between one and fifteen trucks, roughly $300K to $8M in revenue: the shops big enough to have real money moving and small enough that nobody's watching all of it.

We're based in Commerce, Michigan and we work with contractors across Metro Detroit and the entirety of the US. Because we only work in the trades, the books get set up around how an HVAC company actually works with install, service, and maintenance revenue kept separate. A generalist bookkeeper can keep an accurate ledger without any of that built in; the difference is whether the ledger can actually answer the questions above.

Austin Wendel, founder of Accounting 4 Trades, in Livonia, Michigan.

Built for how Metro Detroit runs

Metro Detroit isn't one market; it's a dozen. The custom-home corridor across Oakland County, like Birmingham, Bloomfield, Troy, Rochester, Northville, Novi, runs on high-ticket installs and premium expectations. Macomb and the Downriver communities lean on a huge base of postwar housing, where replacement and repair keep the calendar full year-round. West into Livingston, Brighton, Howell, Hartland, it's newer builds and rural runs where windshield time up US-23 eats margin if nobody's tracking it. Different work, different cost structure, different numbers to watch.

A few Michigan-specific rules shape the books no matter which corner of the metro you work:

Sales Tax

On an install you're the consumer of the equipment and you pay the 6% when you buy it and don't charge the homeowner. BUT, if you sell a part or filter over the counter that now makes you a retailer who has to collect it. Two different rules, one shop.

Detroit City Taxes

Crews working inside Detroit owe city income tax on that share of their pay. Most suburbs and Ann Arbor don't tax at all, so payroll depends on the route and job that week.

Rebates

Offer a DTE or Consumers instant rebate and you front the discount at the sale, then wait six to eight weeks to be paid back. Until that check lands, it's a receivable and easy to lose track of.

Calendar Swings

A Michigan HVAC year runs hot and cold: the furnace-season rush, two shoulder-season lulls, and a brief condenser spike mid summer. Cash flow that isn't planned around that swing is what quietly sinks otherwise-busy shops.

Where We Work

HVAC contractors across Wayne, Oakland, Macomb, and Livingston counties from Downriver up I-75 to Auburn Hills, out M-59 across Macomb, and along the I-696, I-94, and I-96 corridors. Livonia, Troy, Warren, Sterling Heights, Dearborn, Royal Oak, Novi, Rochester Hills, Canton, and the Oakland County suburbs. Based in Commerce, MI and working remotely, so the whole metro is covered.

What we find when we open the books

A Financial Leak Detection diagnostic is a look at what's already in your books before anything else. Here's a sampling of what real ones have surfaced. These are anonymized, but straight off actual contractors' ledgers:

$1.6M

in customer payments sitting unrecorded in one contractor's books - 1,777 deposits that never hit the ledger.

$1.5M

in income left uncategorized - real revenue the owner could not see, plan around, or prove.

~$1M

in aged receivables nobody was chasing - work completed, invoiced, and quietly written off by neglect.

$28K

in personal spending run straight through a business's books - a clean audit trail nobody had drawn.

~$12K/mo

in employee theft flagged the moment the books were clean enough to show a pattern.

These are real numbers.

Every figure above came out of an actual contractor's books during a diagnostic. We surface it - what you do next is your call.

Figures are drawn from real client diagnostics and shown anonymized. Amounts reflect what was surfaced in the books, not a guarantee of results.

What working together looks like

Working with us runs through two stages. First, the diagnostic above creates a review of your existing books that shows where money is going sideways and what needs fixed. Then, if it's a fit, monthly bookkeeping built for how an HVAC company runs keeps it clean moving forward:

Clean books, every month

Categorized, reconciled, and closed on a schedule you can count on.

Job & revenue-line clarity

See which work makes money - install, service, and maintenance, split out.

Cash flow through the seasons

Visibility that holds up through the furnace-season rush and the shoulder-season lull.

CPA-ready at tax time

Your accountant gets a clean set of books, not a shoebox in April.

Known by name

A boutique roster means you talk to people who know your shop, not a call center.

How It Works

Profit Leak Audit
- We ensure we understand your pain points and walk through your current books with you to check for major leaks at the surface - free, no obligation.
Financial Leak Detection
- We do a full deep dive into your books and produce a report that details all of the errors as well as the proposed solution to ensure we're both on the same page.
Cleanup & Catch-Up
- We resolve all of errors we found and begin implementing the proposed systems and solutions.
Monthly Bookkeeping
- You get clear, job-level financials every month so that your numbers are now working for you.

Accounting 4 Trades onboarding process: Profit Leak Audit, Financial Leak Detection, Cleanup and Catch-Up, and Monthly Bookkeeping.

What to look for in an HVAC bookkeeper

Whoever ends up keeping your books, us or someone else, a handful of things separate a bookkeeper who helps you run an HVAC company from one who just keeps a tidy ledger. Worth checking for, whichever way you go:

A generalist bookkeeper vs. a trades-only firm
What matters	Generalist bookkeeper	Accounting 4 Trades
Job-level profit	A company-wide P&L, maybe	Which jobs and revenue lines actually make money
Michigan tax wrinkles	Often misses contractor-as-consumer & city tax	Sales/use tax & Detroit withholding handled by default
Utility rebates	Booked whenever, if at all	Tracked as receivables so nothing is lost
When you call	A ticket in a queue	The people who already know your books
Pricing	Hourly, unpredictable	Flat monthly, trades-only

Boutique by Design

We cap our roster on purpose. A boutique firm that knows every client by name beats a bookkeeping mill that treats you like an account number. Founder Austin Wendel is the face of the firm and the person you'll talk to first, backed by a fulfillment team that handles the day-to-day.

Proof from the Field

Grizzly Heating and Air

"Austin has been a great asset to our operations. His communication and professionalism are on point and his reports are delivered consistently on time, clear to read, and include his insights as well. There are a lot of recurring services businesses use that seem like a wise use of funds but end up falling short, Accounting 4 Trades is NOT one of those-money well spent!"

Mountain West Heating & Air Conditioning

"Austin is the man when it comes to accounting for the trades (see what I did there) but seriously, Austin is detailed and up to date on modern accounting processes and provides not only detailed reporting at the end of the month, but follows up with a detailed recording going through the report in detail with commentary. He is easily reachable and I have referred him to other contractors and he follows through every time. If you need accounting services for your HVAC company, this is your company."

Frequently Asked Questions

Do you do our taxes?

No, we do bookkeeping and CFO work. We hand your CPA clean books at tax time.

Do we have to be in Detroit?

No. We're remote and cover the entire Metro Detroit area such as Wayne, Oakland, Macomb, and Livingston as well as the rest of the USA. Location isn't a barrier.

How is trades-only bookkeeping different from a general bookkeeper?

A trades-focused bookkeeper builds your books around install, service, and maintenance revenue and handles the Michigan rules that apply to contractors: contractor-as-consumer sales tax, Detroit withholding, rebate receivables. A generalist can keep an accurate ledger without that context built in.

Do HVAC contractors charge sales tax on installs in Michigan?

Usually not, on an install you pay the tax when you buy the equipment, as the consumer.

However, if you're selling just parts to customers, then those are taxed differently.

Do you work with QuickBooks, ServiceTitan, Housecall Pro, or Jobber?

Yes. We keep your books in QuickBooks and work alongside the field software you already run, so job data ties back to clean financials. No switching systems.

What size HVAC companies do you work with?

Roughly one to fifteen trucks, generally $300K to $8M in revenue.

How do you price, and is there a contract?

Flat monthly pricing based on the size and complexity of your books. No hourly billing. No surprise invoices. We start with the diagnostic so both sides know what we're working with.

What's in the free audit?

It's typically a live call where we review pain points, any open questions you have, and dive into your QuickBooks and FSM via a screenshare so we can highlight top level issues that we see everyday. We review your current books and show you what's leaking. No obligation to continue.

Book a Free Profit Leak Audit

If any of this sounds like your books, the Profit Leak Audit is a no-cost look at what's actually in your numbers - where money's leaking and what it would take to close the gaps. No obligation, and a 90-day money-back guarantee if you decide to work with us.

Maximize Your Profit—Let’s Talk

Related Resources

HVAC Bookkeeping: https://acc4t.com/hvac
The Phases of an HVAC Growth: https://acc4t.com/hvac-bookkeeping-by-stage
Free Resources for all HVAC Owners: https://acc4t.com/resource-5908
- Chart of Accounts
- Labor Burden Calculator
- Typical Leaks We See
- and More

90-Day Moneyback Guarantee

We stand by our work—no excuses, no fine print. If you're not 100% satisfied within the first 90 days, we'll refund up to 50% of one-time investments or 100% of recurring service fees. Your success is our priority, and we’re confident in delivering results that matter.