A CPA for small business owners in Portland

Why Portland owners want a CPA for small business work who knows the local rules

Most small business owners expect a federal return and a state return. In Portland you also have a combined City of Portland and Multnomah County business tax return, possible Metro taxes, and Oregon payroll programs such as the transit taxes and Paid Leave Oregon. Miss one and the penalty letters start arriving months later, usually after you have already moved on to the next busy season.

A CPA for small business clients in the Portland area spends a lot of time on those local layers. The federal side looks the same as anywhere else. The difference is everything stacked on top of it, and how the pieces connect. Income you report to the IRS flows into the Portland and Multnomah County return, and payroll you run every two weeks triggers state and regional taxes you may not see on a basic payroll report.

Every request through Accountants Portland goes to a licensed CPA in our Portland area network who handles small business work. You get one person who looks at the whole picture instead of a different preparer for each form.

The combined Portland and Multnomah County business tax return

The City of Portland Revenue Division runs one combined return for the City of Portland Business License Tax and the Multnomah County Business Income Tax. On the 2025 return for individuals (Form SP), the city rate is 2.6% and the county rate is 2%, each with a $100 minimum. The 2025 calendar year return was due 4/15/2026.

The form also has a line for an owner's compensation deduction, which can make a real difference for sole proprietors and partners. How much you can take depends on the instructions for that tax year, so it is worth having a CPA run the numbers rather than guessing.

Larger businesses may also owe the Metro Supportive Housing Services business income tax. Metro describes it as a 1% tax on net income for businesses with gross receipts above $5 million. If you are close to that line, planning ahead matters.

Oregon and Portland area payroll taxes

Hiring your first employee in Portland brings a set of payroll programs that surprise a lot of new employers. Oregon has a statewide transit tax of 0.1% of wages, withheld from each employee. TriMet also charges a transit payroll tax directly to employers in its district, at a rate of 0.8237% for 2025 and 2026.

Paid Leave Oregon adds another line. For 2026 the contribution rate is 1% of wages. Employees pay 60% of it. Employers with 25 or more employees on average pay the other 40%, and smaller employers still have to withhold and send in the employee share.

On top of that, employers inside the Metro area may need to withhold Metro and Multnomah County personal income taxes for employees who earn over $200,000 or who opt in. Your CPA can check that payroll is set up for all of these before the first quarterly filing, not after.

• Statewide transit tax: 0.1% of wages, withheld from employees
• TriMet transit payroll tax: 0.8237% for 2025 and 2026, paid by the employer
• Paid Leave Oregon: 1% for 2026, split 60% employee and 40% employer for employers with 25 or more employees

When the Oregon Corporate Activity Tax applies

Oregon has no general sales tax, but it does have the Corporate Activity Tax, often called the CAT. Despite the name, it is not limited to corporations. It is based on Oregon commercial activity, which the Department of Revenue describes as the total amount a business realizes from transactions and activity in Oregon.

The Oregon Department of Revenue says a business must register for the CAT within 30 days of reaching $750,000 in Oregon commercial activity for the year. A return is required once commercial activity is over $1 million. The tax is $250 plus 0.57% of taxable commercial activity over $1 million, after a subtraction of 35% of the greater of cost inputs or labor costs.

Growing Portland businesses often cross the registration line without noticing, especially in a strong year. A CPA who tracks your receipts through the year can tell you when to register and whether estimated CAT payments are required.

Picking the right structure for your business

Plenty of Portland businesses start as sole proprietors and later form an LLC through the Oregon Secretary of State. The Articles of Organization fee for an Oregon LLC is $100, with a $100 annual renewal. Forming the LLC is the easy part. The tax choices that come after it take more thought.

An LLC can be taxed as a sole proprietor, a partnership, or an S corp. Each choice changes how much self employment tax you pay, what shows up on the combined Portland return, and how much paperwork you take on. An S corp election, for example, means running payroll for yourself and filing Form 1120-S every year.

A good CPA will not push you into a structure. They will model your actual numbers and explain the trade offs in plain language so you can decide.

Bookkeeping that makes tax season easier

Most tax problems for small businesses start long before tax season. Mixed personal and business spending, missing receipts and uncategorized bank feeds turn a simple return into a cleanup project, and cleanup takes longer than doing it right the first time.

Monthly or quarterly bookkeeping keeps your numbers ready for every filing on the calendar, from federal estimates to the Portland and Multnomah County return. It also gives you a clear view of profit, which matters when you are deciding whether to hire, buy equipment, or set money aside for the next tax bill.

Some owners want full bookkeeping. Others keep their own books and want a CPA to review them a few times a year. Either way, say so on the quote form and the CPA will price the work you actually need.

Your personal taxes as a Portland business owner

Profit from a sole proprietorship, partnership or S corp usually lands on your personal return. For Portland area owners that can mean more than the federal 1040 and the Oregon OR-40. The Metro Supportive Housing Services personal income tax is 1% of Metro taxable income above $125,000 for single filers or $200,000 for joint filers for tax years 2021 through 2025, rising to $128,000 and $205,000 for 2026. The Multnomah County Preschool for All tax is 1.5% of Multnomah taxable income above $125,000 single or $200,000 joint, with another 1.5% above $250,000 single or $400,000 joint.

These taxes are filed with the City of Portland, not on your Oregon return, and owners with good years are often caught out by them. Starting with tax year 2026, quarterly estimates for each of them are required once your liability reaches $5,000, with payments due 4/15, 6/15, 9/15 and 1/15.

Federal estimates follow a similar calendar. For 2026 the IRS lists due dates of 4/15/2026, 6/15/2026, 9/15/2026 and 1/15/2027. A CPA who handles your business and personal returns together can set one plan that covers all of them, so a strong quarter does not turn into a surprise bill at tax time.

Common questions