Business tax returns in Portland for every type of entity

Which federal return your business files

Your federal return depends on how the business is taxed, not on what the state paperwork calls it. A sole proprietor, including a single member LLC that has not chosen corporate tax treatment, reports business profit on Schedule C attached to the owner's Form 1040. A partnership, including most multi member LLCs, files Form 1065 and gives each partner a Schedule K-1 showing their share. An S corp files Form 1120-S, and a regular C corporation files Form 1120.

Partnerships and S corps do not usually pay federal income tax themselves. Profit passes through to the owners, who report it on their personal returns. That is why a late 1065 or 1120-S holds up every owner's Form 1040, and why CPAs push to finish them early.

If you are not sure how your business is taxed today, your CPA can tell from your last return or your IRS letters. Changing to S corp treatment means filing Form 2553, which must be filed no more than 2 months and 15 days after the start of the tax year it is meant to cover, or at any time in the year before.

Federal deadlines for business tax returns

Form 1065 and Form 1120-S are due on the 15th day of the 3rd month after the tax year ends. For calendar year 2025 returns, that date fell on a Sunday, so the deadline moved to 3/16/2026. Form 1120 is due on the 15th day of the 4th month, which was 4/15/2026 for calendar year 2025. Schedule C is part of the owner's Form 1040, so it follows the individual 4/15 date.

Form 7004 gives partnerships and S corps an automatic six month extension to file, and corporations use it too. As with personal returns, more time to file is not more time to pay. An S corp that extends is expected to deposit any estimated tax it owes when it files the extension.

Extensions are common and nothing to worry about on their own, but they push back the K-1 forms that owners need for their personal returns. If you own part of a partnership or S corp, ask early when your K-1 will be ready, because your own Form 1040 and Oregon return cannot be finished without it. A late K-1 is one of the most common reasons an owner has to extend a personal return.

Oregon business returns

Oregon has its own return for each entity type. Partnerships with Oregon source income or an Oregon resident partner file Form OR-65, due 3/15 for calendar year filers, and a valid federal extension also counts for Oregon. S corps doing business in Oregon or receiving Oregon income file Form OR-20-S and pay a $150 minimum excise tax. C corporations doing business in Oregon file Form OR-20 and pay the greater of their calculated tax or a minimum tax based on Oregon sales.

Oregon corporation returns, both OR-20 and OR-20-S, are due on the 15th day of the month after the federal due date. The Oregon extension date works the same way, one month after the federal extended date.

Larger businesses also face the Corporate Activity Tax (CAT), which is a tax on Oregon gross receipts rather than profit. A business must register within 30 days of reaching $750,000 in Oregon commercial activity and must file a return once it passes $1 million. The tax is $250 plus 0.57 percent of taxable commercial activity above $1 million, and the return is due on the 15th day of the 4th month after the tax year ends.

The Portland and Multnomah County combined business tax return

Businesses operating in Portland or Multnomah County file one business tax return with the City of Portland Revenue Division. That return covers the City of Portland Business License Tax, the Multnomah County Business Income Tax and, for larger businesses, the Metro Supportive Housing Services Business Income Tax. You file it through Portland Revenue Online or approved tax software, and you attach pages from your federal and Oregon returns.

The return is due on the 15th day of the 4th month after the tax year ends, generally 4/15 for calendar year filers. A six month extension moves the filing date to 10/15, but payment is still due 4/15. C corporations get an automatic one month extension so the local date lines up with the Oregon corporate return, though the payment date does not move.

Small businesses are not off the hook just because they owe nothing. Portland exempts businesses with gross receipts under $50,000 for tax years through 2025, under $75,000 for 2026 and under $100,000 from 2027 on. Multnomah County exempts gross receipts under $100,000. Metro SHS business tax applies only above $5 million in gross receipts, and sole proprietors owe the Metro personal tax instead. Businesses exempt from the City and County taxes must still file the return to claim the exemption.

The Oregon PTE-E election for partnerships and S corps

Oregon lets partnerships and S corps elect to pay the Pass Through Entity Elective (PTE-E) tax at the business level. The rate is 9 percent on the first $250,000 of distributive proceeds and 9.9 percent above that, and the owners then claim a credit for the tax paid on their share. Oregon created it in response to the federal cap on state and local tax deductions.

The election is made each year by filing Form OR-21 by its due date, including extensions, and it is available for tax years beginning before 1/1/2028. Late returns are not accepted, so the decision has to be made on time. Whether it helps depends on the owners, their other income and the federal rules for that year, which is a question to raise with your CPA well before the deadline.

Because the election belongs to the business but the credit belongs to the owners, everyone needs the same information. The business must file its PTE-E return before it issues the OR-21 K-1 forms to members, or the credits can be disallowed, so the order of filing matters.

What your CPA needs and how quotes work

A clean set of books makes a business return faster and cheaper to prepare. Your CPA will usually ask for a year end profit and loss statement, a balance sheet, bank and loan statements, payroll reports, a list of equipment bought or sold, and last year's federal, Oregon and local returns.

First year businesses should also have their formation papers handy: the Oregon business registration, the IRS letter assigning an employer identification number and any S corp election. These tell the CPA which returns are required and which year they start.

Tell us what you need and a licensed CPA who works with businesses like yours gets in touch with a clear, fixed quote. If your books are behind, say so on the form. The CPA can quote the cleanup and the return together.

Common questions