State tax compliance means meeting every obligation each state imposes on you to register, file returns, collect and remit sales tax, withhold from employee wages, and pay what you owe based on where you live, work, or do business. State rules run on their own tracks, so satisfying the IRS does not satisfy any state. Nine states impose no individual income tax on wages, but every state has some combination of income, sales, payroll, franchise, or gross receipts taxes that can reach you, and the enforcement tools include liens, wage levies, and revoked business licenses.
Where You Owe: Figuring Out Nexus
Nexus is the legal connection that gives a state the right to tax you. Traditionally it meant physical presence: an office, a warehouse, employees on the ground, a sales rep visiting for a few days. That test still applies and catches more people than expected. Storing inventory in a third-party fulfillment center, sending a technician to a client site, or leasing equipment across state lines can all create physical nexus.
The bigger shift came in 2018 with South Dakota v. Wayfair, Inc., when the Supreme Court held that states can impose tax obligations based on economic activity alone. A state tax is valid so long as it applies to activity with a substantial connection to the state, is fairly apportioned, does not discriminate against interstate commerce, and is fairly related to the services the state provides.1Justia Law. South Dakota v. Wayfair, Inc.
After Wayfair, every state with a sales tax adopted economic nexus thresholds. The most common is $100,000 in annual sales into the state. Some states originally added a 200-transaction trigger, but that count-based test has been steadily disappearing. As of 2026, more than a dozen states have eliminated the transaction test entirely, including Colorado, Indiana, North Carolina, South Dakota, and Washington. Each state sets its own numbers, so you have to track sales into every state individually. Crossing a threshold triggers an obligation to register, collect, and remit, often retroactive to the date you first exceeded it.
Affiliate nexus is a third category worth watching. The activities of a related company, franchisee, or independent contractor using your trademarks in a state can create a tax obligation for the parent entity, even where you have no employees or property of your own there. Regular review of sales data, employee locations, and affiliate relationships is the only reliable way to catch new nexus obligations before a state does.
Individual Income Tax and Multi-State Workers
Nine states impose no individual income tax on wages and salaries: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming.2Tax Foundation. State Individual Income Tax Rates and Brackets, 2026 If you live and work only in one of those states, you file no state return on your earnings. Everywhere else, you owe income tax to the state where you physically perform the work. Live in one state and commute to another, and you generally file in both, with your home state granting a credit for taxes paid to the work state so the same income isn’t taxed twice.
States disagree about when a nonresident’s work triggers a filing obligation. As of January 2026, 22 states require nonresidents to file if they work even a single day in the state. Others set thresholds ranging from 12 to 60 days. A handful require both a day count and an income threshold before filing is mandatory.3Tax Foundation. Nonresident Income Tax Filing and Withholding Laws by State
Employer withholding rules layer on top. Some states require withholding from day one of a nonresident employee working in the state; others allow 14, 30, or 60 days before withholding kicks in. Employers with traveling workforces have to track work days by state for each employee.3Tax Foundation. Nonresident Income Tax Filing and Withholding Laws by State
The Convenience of the Employer Rule
A small group of states applies the “convenience of the employer” rule, which taxes remote workers based on where the employer’s office sits rather than where the employee actually works. If you work from home in one state for an employer headquartered in a convenience-rule state, that employer’s state may tax your wages as if you were at headquarters. As of early 2025, the states applying some form of this rule include Alabama, Connecticut, Delaware, Nebraska, New Jersey, New York, Oregon, and Pennsylvania, though the details vary. New York is the most aggressive, requiring employees to prove their remote work location qualifies as a bona fide employer office to escape the rule.
Reciprocity Agreements
Reciprocity agreements between neighboring states offer relief for commuters. When two states have one, you pay income tax only to your home state even if you physically work in the other. About 30 reciprocal agreements exist, involving 16 states and the District of Columbia, concentrated in the Midwest and Mid-Atlantic. If yours applies, file a withholding exemption form with your employer so tax is withheld only for your home state. Skip that step and you’ll pay both, then have to file in the work state to get a refund.
Business Income Tax and Apportionment
Businesses operating in multiple states don’t pay tax on all their income to every state where they have nexus. They use apportionment formulas to divide income among the states entitled to tax it. The formula usually considers some combination of property, payroll, and sales in each state relative to nationwide totals. Many states now weight the sales factor most heavily or use a single-factor sales formula, which favors companies with significant property and employees inside the state but customers spread elsewhere.
State returns generally require disclosure of your federal tax information so the state can verify consistency between the two filings. If you’re claiming a credit for taxes paid to another state, you’ll need a copy of that state’s return to substantiate the claim. Inconsistent apportionment across returns is one of the fastest ways to trigger an audit.
Gross Receipts and Franchise Taxes
“No income tax” doesn’t mean “no state taxes” for businesses. Nevada, Ohio, Texas, and Washington impose a gross receipts tax rather than a traditional corporate income tax. A gross receipts tax applies to total revenue before deducting expenses, so a business can owe tax even in a loss year. Delaware, Oregon, and Tennessee layer a gross receipts tax on top of their corporate income tax. South Dakota and Wyoming impose neither.4Tax Foundation. State Corporate Income Tax Rates and Brackets
Some states also impose a franchise tax, charged for the privilege of doing business there. The name has nothing to do with franchise agreements. Franchise taxes often resemble income taxes but may use a different base, such as net worth or capital. Before expanding into a new state, check whether it imposes an income tax, a gross receipts tax, a franchise tax, or some combination.
Sales and Use Tax
If you sell taxable goods or services, you need a sales tax permit in every state where you have nexus. The permit authorizes you to collect tax from customers and obligates you to remit those funds on a regular schedule. Tracking which sales are taxable and which are exempt is significant work. Government agencies, wholesalers, and certain nonprofits may qualify for exemptions, but the burden is on you to collect and keep valid exemption certificates for every non-taxable transaction. Fail to produce a certificate during an audit and you owe the uncollected tax.
Use tax is the mirror image. When you buy from a seller who didn’t collect sales tax, typically an out-of-state purchase, you owe use tax directly to your own state at the same combined rate you’d have paid locally. Combined state and local sales tax rates range from under 5% in some areas to over 11% in others.5Tax Foundation. State and Local Sales Tax Rates, 2026 Use tax is widely owed and widely ignored, which makes it a routine audit target.
Marketplace Facilitator Laws
If you sell through a large online platform, the platform likely handles sales tax collection for you. Nearly every state with a sales tax has enacted marketplace facilitator laws that shift the collection obligation to the platform hosting the sale. Major e-commerce marketplaces are responsible for collecting and remitting sales tax on transactions made through them, even where the individual seller wouldn’t independently meet the state’s nexus threshold. You still need to know where you have nexus and verify the platform is collecting correctly, but the heaviest lift moves off your desk for sales in those channels.
Filing Frequency
States assign sales tax filing frequency based on the volume you collect. Low-volume sellers may file annually or quarterly; high-volume sellers file monthly. Some states reassign your frequency automatically as collection amounts change. Missing a sales tax deadline is treated more seriously than missing an income tax deadline in many states, because sales tax is money you already collected from customers and hold in trust for the state. Keeping collected sales tax in a separate account prevents the common mistake of spending it before the remittance date.
Employer Withholding and Payroll Taxes
Every employer in a state with an income tax must withhold state tax from employee wages and remit it. The amount is based on the employee’s earnings and the information they provide on state-specific withholding forms. Deposit schedules vary: smaller employers may remit quarterly, larger ones monthly or semi-weekly. At year-end, you reconcile total withholding against amounts reported on employee W-2 forms.
Employers also owe State Unemployment Insurance (SUI) taxes, which fund unemployment benefits for workers who lose their jobs through no fault of their own.6Employment & Training Administration. Unemployment Insurance Tax Topic SUI rates vary by state and by employer, with new businesses typically paying a standard rate that adjusts over time based on layoff history. Some jurisdictions add local or municipal payroll taxes on top of state-level obligations, creating extra filings tied to the specific city or county where each employee works. Payroll tax errors compound fast because the obligations recur every pay period.
Deadlines and Extensions
Most states that impose individual income tax align the filing deadline with the federal April 15 date, though a few set different dates. When the deadline falls on a weekend or holiday, it shifts to the next business day. State corporate tax deadlines usually follow the same pattern but can vary more for fiscal-year filers.
Most states offer an automatic six-month extension to file, pushing the deadline to October 15. Some grant it automatically once you have a federal extension; others require a separate state form. The detail that catches people: an extension to file is never an extension to pay. If you owe, the full amount is due by the original deadline. Filing late with an extension avoids the late-filing penalty, but any unpaid balance still accrues interest and potentially a late-payment penalty from the original due date.
Penalties, Interest, and Enforcement
Late filing penalties vary but commonly start around 5% of the unpaid tax per month, capped between 12% and 25% of the balance. Late payment penalties run separately. Interest compounds on top of both. Some states set their interest rate at the prime rate plus a fixed percentage, which for 2026 puts rates around 9% to 11% annually in many jurisdictions. Charges accumulate from the original due date, not from when the state sends a notice, so a return filed years late can easily double the original tax owed just in penalties and interest.
State revenue departments have broad enforcement tools. They can place liens against real estate and other property, levy bank accounts and wages, and in some cases revoke state-issued business licenses, forcing you to stop operating until the debt is resolved. Revenue agencies share information with each other and with the IRS, so unreported income in one state often surfaces through cross-referencing. In the sales tax context, the most common audit trigger is a discrepancy between reported sales and the transaction data payment processors, banks, and marketplace platforms independently report to the state.
Fixing Past Non-Compliance
If you discover you should have been filing or collecting in a state where you weren’t, the worst move is to hope nobody notices. States have long memories and increasingly sophisticated data matching. The better route is a voluntary disclosure agreement (VDA), which most states offer either on their own or through the Multistate Tax Commission’s national program.
A VDA typically works this way: you approach the state, or the MTC if you owe in several states, before the state contacts you, agree to register, file back returns for a limited look-back period, and pay the tax owed plus interest. In exchange, the state waives penalties and limits your exposure to the agreed look-back period rather than reaching back to the first date you had nexus. The MTC’s Multistate Voluntary Disclosure Program coordinates this process across multiple states at once, and the taxpayer’s identity stays confidential until an agreement is signed.7Multistate Tax Commission. Multistate Voluntary Disclosure Program
The critical requirement is that the state hasn’t already contacted you about the tax in question. Once a state sends an inquiry, files a notice, or begins an audit, the voluntary disclosure window closes for that tax type. You then negotiate from a much weaker position, and the full penalty and look-back exposure applies. For businesses that expanded rapidly after Wayfair without tracking nexus, VDAs have become one of the most common cleanup tools, but the window stays open only while the state doesn’t know about you yet.
Keeping Records
Most states require you to retain records supporting your returns for at least three to four years from the filing date, though some states and some tax types require longer. If you underreported income by a significant amount, the assessment look-back period extends, and your records need to survive that longer window. For sales tax, keep exemption certificates for as long as the statute of limitations on that transaction remains open, because losing the certificate means you’re on the hook for the uncollected tax.
Retain copies of every filed return, confirmation receipts, exemption certificates, apportionment worksheets, and correspondence with state revenue agencies. Digital storage is fine as long as records remain accessible and legible. A missing confirmation receipt when a state claims you never filed is an expensive problem that takes seconds to prevent at filing time.