How Much Should a New Engineering Firm Set Aside for Taxes?

2026-08-21

New engineering firms should set aside 25-35% of net income for taxes. Learn the exact calculation, quarterly payments, and practical steps to avoid penalties.

Starting an engineering firm brings a new set of financial responsibilities, and taxes are often the biggest surprise. As a rule of thumb, set aside 25% to 35% of your net profit for federal and state income taxes, plus self-employment tax if you are a sole proprietor or partner. This range covers most scenarios, but your exact rate depends on your business structure, state, and revenue. Here is how to calculate your specific number and avoid underpayment penalties.

Why 25% to 35% Is the Right Starting Point

Your tax bill is not a flat percentage of gross revenue. It is based on net profit, which is revenue minus deductible business expenses. For a new engineering firm, net profit typically lands between 10% and 20% of gross revenue in the first year, depending on overhead like software licenses, insurance, and subcontractor costs.

On that net profit, you pay:

Federal income tax: 10% to 37% depending on your taxable income bracket (2026 rates).
Self-employment tax: 15.3% if you are a sole proprietor or partner (12.4% for Social Security, 2.9% for Medicare).
State income tax: 0% to 13.3% depending on your state. For example, Texas has no state income tax, while California tops out at 13.3%.

Combined, a sole proprietor in a moderate tax state with $100,000 in net profit might pay roughly 30% to 35% in total taxes. An S-corporation owner who takes a reasonable salary might pay closer to 25% to 30% because they avoid some self-employment tax on distributions.

Use this table to estimate your effective rate based on structure and state:

Business Structure	Federal + Self-Employment	State (Moderate)	Total Effective Rate on Net Profit
Sole Proprietor	30% to 35%	3% to 7%	33% to 42%
Partnership	30% to 35%	3% to 7%	33% to 42%
S-Corporation	25% to 30%	3% to 7%	28% to 37%
C-Corporation	21% (federal) + 0% to 13%	0% to 13%	21% to 34%

Note: C-corporations pay corporate tax rates, but you may also pay personal tax on dividends. Most new engineering firms choose an S-corp or LLC to avoid double taxation.

How to Calculate Your Specific Percentage

Do not guess. Follow these steps to find your number:

Estimate your net profit for the year. Use your business plan or year-to-date financials. For example, if you expect $200,000 in revenue and $120,000 in deductible expenses, your net profit is $80,000.
Add self-employment tax if you are a sole proprietor or partner. Multiply net profit by 15.3% (for 2026, the Social Security wage base is $176,100, so most new firms pay the full rate). For $80,000, that is $12,240.
Calculate federal income tax using the 2026 brackets for your filing status. For a single filer with $80,000 taxable income, the federal tax is roughly $12,000 to $15,000.
Add state tax. Use your state’s rate. For a 5% flat rate, that is $4,000.
Total tax bill: $12,240 + $13,500 + $4,000 = $29,740. That is 37% of net profit, so set aside 37%.

If your net profit fluctuates, use a conservative estimate. Better to over-set-aside and get a refund than to underpay and face penalties.

Quarterly Estimated Payments: What You Owe and When

The IRS requires you to pay taxes as you earn income. If you expect to owe more than $1,000 in federal taxes, you must make quarterly estimated payments. The due dates for 2026 are:

April 15, 2026 (for income earned January 1 to March 31)
June 15, 2026 (for income earned April 1 to May 31)
September 15, 2026 (for income earned June 1 to August 31)
January 15, 2027 (for income earned September 1 to December 31)

Each payment should be 25% of your total estimated tax for the year. If you miss a payment, the IRS charges a penalty based on the underpayment amount and the number of days late. The current penalty rate is around 8% per year, compounded daily. For a $10,000 underpayment, that could be $800 in penalties over a year.

To avoid penalties, use the safe harbor rule: pay at least 100% of your previous year’s tax liability (or 110% if your adjusted gross income was over $150,000). If your first year, you have no prior liability, you must pay 90% of your current year’s tax by the fourth quarter, or you may face a penalty.

Practical Steps to Set Aside Money This Week

Do not wait until April. Take these actions now:

Open a separate business savings account for taxes. Transfer a percentage of every client payment immediately. For example, if you bill $5,000, move $1,500 (30%) to the tax account.
Calculate your effective rate using the worksheet above. Use your actual numbers, not a generic guess. If you are unsure, use 30% as a baseline and adjust after your first quarter.
Set up quarterly reminders in your calendar for the due dates listed above. Mark them two weeks before to give yourself time to prepare.
Use accounting software like QuickBooks or Xero to track income and expenses. Most have a tax estimate feature that updates in real time.
Consult a CPA who works with engineering firms. They can help you choose the right structure and identify deductions specific to engineering, such as software subscriptions, professional liability insurance, and continuing education.

Common Deductions for Engineering Firms

To reduce your net profit and thus your tax bill, take advantage of these deductions:

Software and tools: CAD software, project management tools, and cloud storage (e.g., AutoCAD, Revit, Asana).
Professional liability insurance: Often $2,000 to $5,000 per year for a small firm.
Home office: If you work from home, you can deduct a portion of rent, utilities, and internet.
Business travel and meals: Client meetings, site visits, and industry conferences.
Continuing education: Licensure renewal, courses, and certifications.
Equipment and furniture: Computers, desks, and printers, either as immediate expensing (Section 179) or depreciation.

Keep receipts and log mileage. A CPA can help you maximize these deductions legally.

FAQ

What if I don’t make a profit in my first year? If you have a net loss, you owe no income tax, but you may still owe self-employment tax if you had any net earnings. You can carry the loss forward to offset future profits. Set aside 0% for income tax, but keep a small buffer for state minimum taxes if your state has them.

Can I pay taxes from my business account instead of a separate savings account? Yes, but a separate account reduces the risk of spending the money. Treat it as a liability account, not profit. Many banks offer free business savings accounts with no minimum balance.

What is the penalty for not making quarterly payments? The IRS charges a penalty of about 0.5% of the underpaid amount for each month it is unpaid, up to 25%. The rate can change, but it is roughly 8% annually. For example, a $5,000 underpayment for 6 months could cost you $150 in penalties.

Should I incorporate to lower my tax rate? An S-corporation can reduce self-employment tax, but it adds payroll costs and filing fees. For a new firm earning under $50,000 in net profit, the savings may not outweigh the complexity. Compare your specific numbers with a CPA.

The Bottom Line

Set aside 25% to 35% of your net profit for taxes, but calculate your exact rate using your business structure, state, and projected income. Open a separate tax savings account, transfer a percentage of every payment, and make quarterly estimated payments on time. If you are unsure, start with 30% and adjust after your first quarter. The cost of underpaying is penalties and stress; the cost of overpaying is a refund, which is a better problem to have. Take action this week: estimate your net profit, set your percentage, and schedule your first quarterly payment.