DC Form D-30 vs. D-40: Which Does Your Business File?

If you’re running a business in Washington DC, tax season can feel like navigating alphabet soup. Between federal requirements, state obligations, and District-specific forms, it’s easy to get confused about what you actually need to file. Two forms that often trip up DC business owners are Form D-30 and Form D-40—and filing the wrong one (or both incorrectly) can lead to penalties and headaches.

The good news? The difference between these two forms is straightforward once you understand the basics. Let’s break it down so you know exactly which form applies to your business.

What Is DC Form D-30?

DC Form D-30 is the District of Columbia Unincorporated Business Franchise Tax Return. This form applies to most unincorporated businesses operating in DC, including sole proprietorships, partnerships, and LLCs taxed as partnerships or sole proprietorships.

The D-30 calculates your franchise tax liability based on your business gross receipts. DC’s franchise tax is a flat annual tax on the privilege of doing business in the District, separate from your income tax obligation. Think of it as a license fee for operating in DC.

Key things about the D-30:

• Required for most unincorporated businesses with DC nexus
• Based on gross receipts, not net income
• Due by the 15th day of the 4th month after your tax year ends (April 15 for calendar-year businesses)
• There’s a minimum tax and an exemption threshold—currently, businesses with less than $12,500 in gross receipts may be exempt
• Includes a BPOL (Business and Professional Licenses) tax component

If you’re a sole proprietor or operate an LLC in DC, there’s a strong chance you’ll need to file this form.

What Is DC Form D-40?

DC Form D-40 is the District of Columbia Individual Income Tax Return. This is the personal income tax form you file to report all income earned during the tax year and claim deductions and credits.

The D-40 is what most DC residents and residents working in DC need to file annually—it’s essentially DC’s version of your federal 1040. If you’re self-employed or own a business, your business net income flows onto this form.

Key things about the D-40:

• Required for individuals with DC income tax liability
• Reports total income (wages, business profit, investment income, etc.)
• Due April 15 (same as federal taxes)
• Self-employed individuals report net business income here
• You can claim personal exemptions, standard or itemized deductions, and credits

The D-40 is your personal tax return, regardless of whether you own a business.

Do You File D-30, D-40, or Both?

This is the critical question. Here’s the simple answer:

If you own an unincorporated business in DC and have net income, you file BOTH forms.

Here’s why: The D-30 pays your franchise tax on gross receipts. The D-40 pays your income tax on your net income. They serve different purposes and are calculated differently. One doesn’t replace the other.

However, there are exceptions:

• If your business is incorporated (C-corp or S-corp): Your corporation files its own DC return; you file only the D-40 personally for your wages and investment income.
• If you’re below the exemption threshold: With gross receipts under the current exemption amount, you may not need to file a D-30, but check current DC tax guidance.
• If your business operates outside DC: You may not owe DC franchise tax, but if you live in DC or earned DC-source income, you still file a D-40.
• If you have no net income: You might still owe franchise tax, even if your business loses money, because the D-30 is based on gross receipts, not net profit.

Special Situations: Federal Contractors and Professional Service Firms

Federal contractors, law firms, medical practices, and consulting businesses in the DC metro area should pay special attention. Some of these entities may have different filing requirements or exemptions under DC tax code. For example, certain IOLTA trust accounts maintained by law firms have specific treatment under DC tax rules.

If your business model is complex or involves multiple income streams across DC, Maryland, and Virginia, the filing requirements can get nuanced fast.

Getting It Right

Filing the wrong form or missing a deadline can result in penalties and interest. The District also requires proper business tax preparation to ensure you’re meeting all obligations while claiming every deduction available.

If you’re uncertain whether your DC business needs to file a D-30, a D-40, or both, or if you want to ensure your 2024 filings are handled correctly, book a free consultation with Capital Accounting Group. We work with small business owners across DC, Maryland, and Virginia, and we can walk you through your specific situation so you can focus on growing your business, not worrying about tax forms.