When Your Crew Crosses the State Line, So Does the Tax Bill
I was half-watching a tournament the other night when the camera drifted to the bench — the coaches, the trainer, the two people in matching polos whose jobs I couldn't quite identify. And because I've apparently reached the stage of life where a sideline makes me think about apportionment, I started wondering what all those people owe in taxes for following a team across a dozen jurisdictions.
There's a name for it. They call it the jock tax, and the short version is this: a professional athlete doesn't get to pay income tax only where they live. They pay it in nearly every state they suit up in, because that's where the work was performed. States figure out each player's bill using what's known as the duty-days method — total compensation multiplied by the share of working days spent inside that state's borders. Play three games in California, and California wants its slice of those three games' worth of salary.
It's easy to file that under "problems I will never have." But here's the thing I keep coming back to with my construction and real estate clients: the principle behind the jock tax isn't about sports at all. It's about where work happens. And the day your crew loads up the truck and pours a foundation across a state line, you've just played an away game too.
The rule that doesn't care that you're not famous
The foundational idea in state taxation is that income is taxed where it is earned, not merely where you live. Your home state taxes you on everything — that's residence-based taxation. But other states get to reach in and tax the income that was sourced inside their borders, and then your home state hands you a credit so you're not taxed twice on the same dollar. (California grants that credit under R&TC §18001, and it is rarely as generous in practice as it sounds on paper.)
For an athlete, the trigger is a game. For a contractor, the trigger is physical presence doing the work — and construction is about as physical as presence gets. You can't pour concrete remotely.
This is where a lot of small operators get a nasty surprise, so let me be precise about it. There's a federal law, Public Law 86-272 (15 U.S.C. §§381–384), that shields out-of-state businesses from income tax in a state if their only activity there is soliciting orders for sales of tangible personal property. It sounds like a lifeline. It is not yours. P.L. 86-272 protects salespeople, not tradespeople — it expressly does not cover services or work on real property. The moment your people are building something in another state, you have crossed the line the statute draws, and you have likely created nexus: a connection substantial enough that the state may tax you.
And nexus has only gotten easier for states to assert. Since South Dakota v. Wayfair (2018), states no longer need your boots on their ground at all in some contexts — economic activity alone can be enough. For a contractor with actual boots on actual ground, the question isn't really whether you've created nexus. It's how many obligations came with it.
What an away game actually costs you
Here's where the contractor's situation diverges from the athlete's, and the difference matters. The ballplayer has one clean question — what slice of my salary belongs to this state. You have at least four.
Your business owes an apportioned share of income. If you operate through a pass-through or a corporation, the other state taxes the portion of your business income attributable to activity there, calculated through an apportionment formula (typically built on sales, and increasingly on sales alone). That's the entity-level version of duty days.
You, the owner, may owe a nonresident return. Pass-through income flows to you personally, and the state where it was earned wants a nonresident individual return from you for its share. One out-of-state job can mean two extra returns — one for the business, one for you.
Your payroll obligations travel with your crew. This is the one that quietly bites. When your W-2 employees perform work in another state, you may be on the hook to withhold that state's income tax on the wages earned there — apportioned, essentially, by workdays. It's the duty-days method wearing a hard hat. Miss it, and the liability is yours, not your employee's.
And it runs the other direction, too. When an out-of-state contractor comes to work in California, the party paying them often must withhold 7% of payments for the California-earned portion under R&TC §18662 [verify 2026 — withholding rate and the per-payee dollar threshold against current FTB guidance]. So if you're hiring a specialty sub from Nevada or Arizona for a Torrance job, the withholding question lands on your desk.
One thing I'll flag that isn't tax at all but trips people up constantly: licensing. Your CSLB license stops at the California line. Most states require their own contractor license before you can legally bid or build there, and a few will void a contract — and your right to get paid — if you weren't licensed when the work was done. Worth a phone call before the truck leaves.
California is the aggressive home team
If you're reading this from the South Bay, understand the posture of your own state, because it shapes everything. The Franchise Tax Board is, to put it diplomatically, thorough.
California defines "doing business" expansively under R&TC §23101, and it includes bright-line economic thresholds — cross a certain dollar amount of California sales, property, or payroll and you're "doing business" here whether you wanted to be or not. Those thresholds are indexed for inflation and adjust annually [verify 2026 — current §23101(b) sales/property/payroll amounts]. Source-of-income rules for nonresidents live in R&TC §17951 and its regulations. And for how California carves up business income, the state uses single-sales-factor apportionment (R&TC §25128.7) with market-based sourcing for services (R&TC §25136) — meaning, broadly, California claims the revenue based on where your customer received the benefit, not where you did the work.
The practical translation: California works hard to keep its residents and their income inside the net, and it does not let go easily.
A quick word for the individual tradesperson
If you're not running the company but working it — a W-2 specialist who travels, or a 1099 sub — the classification matters more than it should. An independent contractor reports on Schedule C and deducts legitimate business costs (tools, mileage, equipment) directly against that income. A W-2 employee, under current law, generally cannot deduct unreimbursed job expenses at all, because the misc itemized deduction was suspended by IRC §67(g). That suspension was written to run through 2025, and whether it survives into this year depends on recent federal legislation [verify 2026 — §67(g) status post-2025 tax legislation]. Don't assume either way — it's a real dollar difference, and it's exactly the kind of provision that quietly changes.
My honest take
I'll say what I think, because you can get the neutral version anywhere. The multistate system we've built rewards size. A national builder has a tax department that files in thirty states without blinking. The two-truck outfit that lands one good job across the Nevada line faces, proportionally, a far heavier compliance burden for that same dollar of revenue — more returns, more withholding mechanics, more exposure if it's missed. States have leaned into aggressive sourcing because mobile income is a reliable place to find revenue, and the people least equipped to navigate it are usually the ones who get the letter. That's not a conspiracy; it's just an incentive structure, and it's one small contractors should plan around rather than discover.
The good news is that none of this is a reason to turn down the away game. It's a reason to price it correctly and structure it before you bid — not after the assessment shows up.
Let's look at your map before you cross the line
If you're weighing work outside California, or you've already done some and aren't sure what it triggered, that's a conversation worth having before a filing deadline forces it. I help South Bay construction and real estate clients map their exposure, structure multistate work, and keep the compliance from eating the margin. Schedule an advisory consultation and let's game-plan it together.
This article is general information and does not create a client relationship or constitute tax advice for your specific situation. If you'd like to share documents related to your circumstances, please use our secure client portal rather than email — never send sensitive financial information through regular email.