If you've ever looked at your paycheck and wondered why two separate chunks of money disappear before it even reaches you, you're not alone. Most Americans — and non-US founders running a US LLC — get confused about how federal tax and state tax actually work together. The short answer: they're two separate tax systems that apply to the same income, collected by two different governments, for two different purposes.
This guide breaks down federal tax vs state tax in plain English — no jargon, no confusing IRS language — so you understand exactly what you're paying, why, and how the two systems interact.
What Is Federal Tax?
Federal tax is the money you pay to the U.S. national government, collected and enforced by the Internal Revenue Service (IRS). It funds nationwide programs — defense, Social Security, Medicare, federal highways, and other services that apply no matter which state you live in.
Federal income tax uses a progressive tax system, meaning the more you earn, the higher the rate on each additional dollar. The IRS currently applies seven federal tax brackets: 10%, 12%, 22%, 24%, 32%, 35%, and 37%. These brackets are adjusted annually for inflation, so the exact income thresholds shift slightly each year. Because of the One Big Beautiful Bill Act passed in 2025, most of the individual tax provisions from the 2017 Tax Cuts and Jobs Act have now been made permanent, which affects planning for 2026 and beyond.
Here's the part that trips people up: a progressive system doesn't mean your entire income is taxed at your top bracket. Only the portion of income within each bracket is taxed at that bracket's rate. This is called your marginal tax rate, and it's different from your effective tax rate — the actual average percentage of your total income that goes to taxes.
What Is State Tax?
State tax is collected by your state's Department of Revenue and funds state-level services — public schools, state police, road maintenance, and Medicaid contributions. Unlike federal tax, state income tax isn't uniform across the country. Each state sets its own rules, and that's where things get interesting.
There are three broad approaches states take:
- Progressive state tax – similar to the federal system, rates increase with income (California, New York, and Hawaii use this model)
- Flat tax – everyone pays the same percentage regardless of income (states like Colorado and Illinois use flat rates)
- No state income tax at all – Texas, Florida, Nevada, Washington, Wyoming, South Dakota, Alaska, Tennessee, and New Hampshire don't tax wage income
This is why the "federal tax vs state tax rate" comparison isn't one-size-fits-all. Someone earning $80,000 in Texas and someone earning $80,000 in California will owe the same federal tax but very different state tax.
How Federal and State Taxes Work Together
This is the core of the guide, so let's slow down here.
Federal and state taxes are calculated separately but often start from a related number. In most states, your state taxable income is based on — or closely follows — the adjusted gross income (AGI) or taxable income you calculate on your federal return. Your state return typically asks you to enter figures from your federal Form 1040, then applies state-specific rules, credits, and deductions.
Here's the step-by-step flow most taxpayers follow:
- Calculate gross income (wages, self-employment income, rental income, dividends, etc.)
- Subtract deductions and adjustments to get federal taxable income
- Apply federal tax brackets to determine federal tax owed
- Use that same base figure (with state-specific adjustments) to calculate state taxable income
- Apply your state's tax rate or brackets to determine state tax owed
- File both returns — federal to the IRS, state to your state's Department of Revenue
Both taxes are usually withheld from your paycheck simultaneously if you're a W-2 employee. Your employer uses your W-4 form for federal withholding and a similar state form for state withholding. If you're self-employed, you handle both through estimated quarterly taxes instead of automatic withholding.
Federal and state taxes don't compete with each other — they run in parallel, each with its own bracket structure, filing deadline (though usually the same date), and refund process. That's also why your federal refund and state refund often arrive at different times and for different amounts — they're calculated by two entirely separate systems.
Federal Tax vs State Tax: Key Differences at a Glance
Collected by — Federal Tax: IRS. State Tax: State Department of Revenue.
Applies to — Federal Tax: All U.S. taxpayers equally. State Tax: Varies by state of residence.
Tax structure — Federal Tax: Progressive (7 brackets). State Tax: Progressive, flat, or none.
Funds — Federal Tax: National programs (defense, Social Security, Medicare). State Tax: State programs (schools, roads, state services).
Filing — Federal Tax: IRS Form 1040. State Tax: State-specific tax return.
Do You Have to Pay Both Federal and State Taxes?
In most cases, yes — if you live and earn income in a state with an income tax, you'll file and pay both. The only exception is if you live in one of the nine states with no state income tax, in which case you only owe federal tax on your wages (though you may still owe other state taxes, like sales or property tax).
There's also a nuance for people who work in one state but live in another. Some neighboring states have reciprocity agreements that let residents pay income tax only to their home state, even if they physically work across the border. Without a reciprocity agreement, you may need to file a return in both states and claim a credit to avoid being taxed twice on the same income.
Payroll Tax vs Income Tax: A Related but Different Category
It's worth separating income tax from payroll tax, since people often lump them together. Payroll tax refers specifically to FICA — the combined Social Security tax and Medicare tax withheld from your paycheck. This is a federal payroll tax, separate from federal income tax, and it funds specific programs rather than the general government budget. State payroll taxes exist too, but they're distinct from state income tax and usually fund things like unemployment insurance.
Why This Matters for US LLC Owners Outside the US
If you're a non-resident running a US LLC — for example, a Pakistani entrepreneur selling on Amazon or Shopify — federal and state tax obligations look a little different from a typical W-2 employee's. Your LLC's federal tax treatment depends on its structure (single-member LLC, multi-member LLC, or electing corporate status), and state tax obligations depend on which state you registered in and where you have "nexus" (a business connection significant enough to trigger tax filing requirements).
This is a common area of confusion, and getting it wrong can mean missed filings or unnecessary tax bills. If you're setting up or already running a US LLC from Pakistan, it's worth reading our breakdowns on registering a US LLC from Pakistan and the full cost of a US LLC from Pakistan in 2026, since state filing fees and franchise taxes vary significantly depending on where you incorporate.
You'll also want to understand your federal reporting identity. Many non-resident founders confuse an EIN with an ITIN — they serve different purposes for federal tax reporting, and using the wrong one (or missing one entirely) is one of the most common mistakes Pakistani US LLC owners make. Our guide on EIN vs ITIN for a US LLC explains exactly when you need each one, and our ITIN guide for non-US residents walks through the application process step by step. If you're an e-commerce seller specifically, our post on what an ITIN means for Amazon and Shopify sellers covers the seller-specific angle.
Beyond income tax, LLCs with foreign ownership have separate federal filing obligations — including BOI reporting and Form 5472 — that exist independently of your annual federal and state tax returns. Missing these isn't a tax bill, it's a compliance penalty, so it's worth reviewing our guide on LLC compliance, BOI, and Form 5472 to make sure nothing falls through the cracks.
Common Mistakes People Make
- Assuming state tax is calculated completely independently of federal tax — in reality, most states start with your federal AGI as the base figure
- Forgetting that moving states mid-year may require filing part-year resident returns in two states
- Not adjusting state withholding after a raise, since state brackets don't always move in step with federal ones
- Assuming "no state income tax" means no state tax at all — you may still pay property tax, sales tax, or excise tax
- Missing quarterly estimated payments as a self-employed person, which applies to both federal and state obligations
FAQs
What is the difference between federal and state tax? Federal tax is collected by the IRS and funds national programs, using the same seven tax brackets nationwide. State tax is collected by each state's Department of Revenue, and the rate — or whether it exists at all — depends entirely on where you live.
Do all states have state income tax? No. Nine states currently have no state income tax on wages: Texas, Florida, Nevada, Washington, Wyoming, South Dakota, Alaska, Tennessee, and New Hampshire.
Is state tax based on federal taxable income? In most states, yes. Your state return typically starts from your federal AGI or taxable income, then applies state-specific deductions, credits, and rates.
Can I owe state tax but not federal tax, or vice versa? Yes. Because the two systems have different deductions, credits, and thresholds, it's possible to owe one without owing the other, especially if you qualify for federal credits that don't have a state equivalent.
Do I file federal and state taxes separately? Yes. You file a federal return with the IRS and a separate state return with your state's tax agency, even though many of the numbers carry over from one to the other.
Why is my state tax refund different from my federal refund? Because they're calculated using entirely separate bracket systems, deductions, and withholding amounts, there's no reason to expect the two refunds to match — they rarely do.
Final Thoughts
Federal tax and state tax aren't competing systems — they're two layers of the same overall tax obligation, each funding different levels of government. Once you understand that state tax generally builds on your federal numbers rather than existing in isolation, the whole process becomes far less confusing.
If you're managing US tax obligations from outside the country — especially as a US LLC owner — getting your federal and state filings right from day one saves you from costly corrections later. Explore our full range of services for US company formation and compliance support, or get in touch with our team to make sure your federal and state tax setup is handled correctly from the start.
For official, up-to-date bracket figures, always cross-check with IRS.gov directly, since thresholds are adjusted annually for inflation.