Most taxpayers don't realize that federal and state tax obligations are handled separately—and sometimes require separate professional help. Whether you need both federal and state tax services depends on your income sources, business structure, and state residency, but understanding the difference can save you thousands in penalties and overpayment.
Why Federal and State Tax Services Aren't Interchangeable
Federal taxes and state taxes operate under different rules, filing deadlines, and penalty structures. The IRS handles federal income tax, self-employment tax, and certain credits, while state tax agencies manage state income tax, sales tax compliance, and state-specific deductions. A tax professional who specializes in federal filings might miss state-level deductions or credits you qualify for—and vice versa. If you live in a state with income tax, work for multiple states, or run a multi-state business, you'll almost certainly need expertise on both fronts.
Some states have no income tax (like Texas, Florida, and Wyoming), which simplifies things. But if you earn income in multiple states or live in one state while working remotely for employers in another, you could owe taxes to both jurisdictions. Filing only federal returns in these situations leaves you exposed to state audits and penalties.
When You Definitely Need Both Services
Self-employed or business owners: If you operate as a sole proprietor, S-corp, or LLC, you need federal tax planning (quarterly estimated taxes, self-employment tax, business deductions) and state-specific payroll or sales tax compliance. Federal and state rules for business deductions diverge—your federal return might claim a home office deduction differently than your state requires.
Remote workers across state lines: Many workers now live in one state but work for companies headquartered elsewhere. Reciprocal tax agreements exist between some states, but they're complex. A dedicated state tax professional can determine whether you owe taxes to your home state, your employer's state, or both.
Investment income and rental properties: Capital gains, dividend income, and rental property depreciation are taxed at both federal and state levels, often at different rates. Your state might apply higher rates to long-term gains, or offer credits the federal government doesn't recognize.
High-income earners: Federal bracket creep and state surtaxes on high earners create planning opportunities that require dual expertise. Some states impose additional taxes on income over certain thresholds (New York's Millionaires Tax, for example), and failing to plan around both creates missed deductions.
Cost Considerations: What You'll Actually Pay
Federal-only tax preparation typically runs $150 to $500 for straightforward returns (W-2 income, simple deductions) and $500 to $2,500 for self-employed or investment-heavy situations. Adding state tax preparation usually costs an additional $100 to $400 per state, depending on complexity.
Full-service tax planning—where a professional coordinates federal and state strategies year-round—ranges from $1,500 to $5,000+ annually, but often saves that amount through optimized deductions, estimated tax adjustments, and entity structuring.
How to Find the Right Professional Help
Look for tax professionals who explicitly list both federal and state credentials. CPA licenses vary by state, so verify that the CPA or tax professional is registered in both your home state and any state where you owe taxes. The IRS maintains a directory of enrolled agents (EAs) who are authorized to represent clients before the IRS, but check if they also handle state matters.
When evaluating IRS & Tax Assistance Centers and tax professionals:
- Ask whether they prepare returns for multiple states and handle multi-state planning
- Confirm they're licensed in or familiar with your specific state's tax code
- Request references from other multi-state business owners or remote workers
- Clarify upfront whether the quoted fee covers both federal and state returns
- Check if they offer estimated tax planning, which often justifies professional fees through savings
Mercoly helps you compare and find trusted IRS & Tax Assistance Centers providers in one place, making it easier to vet professionals with the multi-state expertise you need.
Frequently Asked Questions
Q: Do I need separate tax returns for federal and state if I live in a no-income-tax state? No—you'll only file a federal return. However, if you earn self-employment income, you still owe federal self-employment tax and must file Schedule SE, even in no-income-tax states.
Q: Can one tax professional handle both federal and state, or should I hire separately? One qualified professional can handle both, and it's often preferable since they'll coordinate deductions and credits across both returns. Hiring separately risks missed opportunities or duplicate fees.
Q: What happens if I file federal taxes but forget state taxes? You'll owe back taxes, interest, and penalties to your state (usually 5-10% of unpaid tax annually). States pursue unpaid taxes aggressively—some even revoke professional licenses or hold driver's license renewals until settled.
Use Mercoly to find verified tax professionals who handle federal and state filings in your area.