Summary of What This Blog Covers
- When and why part-time entrepreneurs need to pay estimated taxes
- How self-employment tax affects online business income
- A simple method to calculate quarterly tax payments
- How Insogna supports with tax planning and compliance
You did it. You started the online business you’ve been dreaming about. Whether you’re side-hustling through freelance writing gigs, selling digital planners on Etsy, offering coaching services over Zoom, or building a Shopify empire from your laptop, the leap is real and it’s exciting.
But then the questions start rolling in.
Do I owe taxes on this?
Do I really have to pay quarterly?
What happens if I don’t?
How much should I be setting aside?
And the big one: What are estimated taxes, and how do they actually work for me?
You are not alone in asking. In fact, nearly every part-time entrepreneur we work with at Insogna, a firm with top-rated CPAs in Austin, Texas, starts here. And the good news? This is the beginning of your evolution from side-hustler to savvy, empowered business owner.
Because knowing how to handle estimated taxes isn’t just about staying out of trouble. It’s about stepping fully into your role as a business leader, taking control of your finances, and making smart, proactive decisions that support your goals.
So, let’s make it make sense. One clear, digestible step at a time.
What Are Estimated Taxes?
Estimated taxes are the payments you send to the IRS throughout the year to cover the income you’re earning that doesn’t have taxes automatically withheld like payments from clients, course revenue, product sales, affiliate earnings, or digital downloads.
In other words, if you’re earning income and no one’s taking taxes out of your check for you? The IRS expects you to take care of that.
And here’s the kicker: they don’t want it all in April. They want it quarterly.
Estimated Tax Deadlines:
- April 15 — for income earned January–March
- June 15 — for income earned April–May
- September 15 — for income earned June–August
- January 15 (of the following year) — for income earned September–December
So, yes, even if your business is part-time, if you’re earning money outside of a W-2 job, and it’s not being taxed before it hits your bank account, the IRS wants a piece of it on time.
This applies to side hustles, freelance gigs, online businesses, coaching programs, Etsy shops, e-book sales, and affiliate marketing. If it’s income, and you’re self-employed, it’s taxable.
If you’re not sure whether you need to file? A tax accountant near you (like the ones at Insogna) can assess your income and let you know if estimated payments are required and how much.
Why Do Estimated Taxes Matter for Side Businesses?
Let’s use an analogy. Imagine the IRS as your business’s silent partner. They don’t do any of the work, but they expect a portion of your profits like royalty rights to your hustle.
But unlike a real partner, they won’t send reminders. If you don’t pay them on time, they just show up at the end of the year with a penalty notice. Not fun.
Many part-time business owners make the mistake of thinking they can wait until April to pay their taxes. But in the eyes of the IRS, waiting is not allowed. You’re expected to pay as you earn even if you’re still getting your business off the ground.
When Are Estimated Taxes Required?
Not everyone with a side hustle needs to make estimated tax payments. So let’s break this down.
You must make estimated payments if:
- You expect to owe at least $1,000 in tax for the year after subtracting withholding and credits, and
- Your withholdings (from a W-2 job, for example) are less than:
- 90% of the total tax you’ll owe this year, or
- 100% of your total tax from last year (or 110% if your AGI was over $150,000)
This means:
- If you make $10,000 in side income and owe $2,000 in tax, but your W-2 job withholds an extra $2,000 beyond what you owe on your salary? You’re covered.
- But if your employer isn’t withholding enough or if you don’t have a W-2 job at all, you likely need to make quarterly payments.
Need clarity? That’s what a certified public accountant near you is for. At Insogna, we walk you through the math and build a plan tailored to your actual income and tax situation.
What Counts as Self-Employment Income?
Let’s make this super clear.
You’re earning self-employment income if you receive payments from:
- Selling physical or digital products online
- Freelance or contract work
- Online coaching or consulting
- Rental or Airbnb income
- Memberships, courses, or downloadable content
- Affiliate marketing and brand partnerships
- Payments reported on a 1099-NEC or 1099-K
Basically, if you’re paid without taxes being withheld, and it’s not passive investment income, you’re self-employed in the eyes of the IRS.
That means your income is subject to income tax and self-employment tax.
What Is Self-Employment Tax?
Oh yes, there’s a whole separate tax for that.
Self-employment tax covers Social Security and Medicare. The same taxes your employer would typically split with you if you were a W-2 employee.
When you’re self-employed, you pay both halves:
- 4% for Social Security
- 9% for Medicare
That’s 15.3% of your net income.
So, if you earn $15,000 from your online business and your expenses are $5,000, your net income is $10,000. You owe approximately $1,530 in self-employment tax before income tax is even added.
This is why self-employed individuals often owe more than expected. The self-employment tax is in addition to your income tax.
Need help calculating your self-employment tax liability? Our team of certified CPAs in Austin does that all day, every day and we’d love to walk you through it.
How Much Should You Set Aside?
Here’s a golden rule:
Set aside 25%–30% of your net business income.
This gives you enough to cover:
- Self-employment tax
- Federal income tax
- State income tax (if applicable)
The exact percentage depends on your total income, tax bracket, state, and business expenses. At Insogna, we help clients adjust their reserves based on seasonal patterns and income fluctuations, so they’re never stuck guessing or scrambling.
A Step-by-Step Guide to Calculating Your Estimated Tax Payments
Let’s walk through the process.
Step 1: Calculate your net profit
Total business income minus business expenses = net profit
Step 2: Calculate self-employment tax
Multiply net profit by 15.3%
Example: $10,000 x 15.3% = $1,530
Step 3: Estimate income tax
Use your tax bracket to estimate how much federal income tax you owe on that net income. This will vary depending on your full tax picture (your day job counts too).
Let’s say your marginal rate is 12%. $10,000 x 12% = $1,200
Step 4: Add them up
Self-employment tax + income tax = your total estimated tax obligation
$1,530 + $1,200 = $2,730
Step 5: Divide by four
That’s how much you’ll pay each quarter: $682.50
Want help making this automatic? We can set up your quarterly payments, calendar reminders, and savings systems. That’s what makes Insogna different, we manage estimated tax planning and forecast cash flow needs with you.
What Happens If You Don’t Pay Estimated Taxes?
If you skip or underpay your quarterly payments, you may face:
- IRS penalties and interest
- A surprise tax bill at the end of the year
- More stress than you need or deserve
But don’t panic. We can help you catch up if you’ve missed a payment, and we’ll work with you to avoid penalties moving forward.
Looking for tax help near you or a tax preparer near you who can help with side-business tax planning? You found us.
What If You Receive Money from International Platforms?
If you work with international clients, receive funds through foreign accounts, or store money abroad, you might be required to file an FBAR (Foreign Bank Account Report).
FBAR filing is required if:
- You had more than $10,000 in aggregate across foreign accounts at any point in the year.
Missing this can result in steep penalties, even if no tax is due.
Our enrolled agents and income tax chartered accountants specialize in international compliance. We take care of FBAR filing for digital nomads, e-commerce sellers, and global freelancers.
How Insogna Supports Part-Time Entrepreneurs Year-Round
We know online business income is dynamic. Maybe you have a big launch one quarter, then quiet months of creation and planning. That’s normal and your tax plan should reflect it.
At Insogna, we offer:
- Custom estimated tax projections based on your income
- Quarterly check-ins and updates
- Cash flow planning and tax reserve strategy
- Entity guidance (when to go from sole proprietor to LLC or S-Corp)
- Annual tax filing with zero surprises
Whether you’re searching for a CPA near you, an Austin, TX accountant, or someone who gets your digital business world, you’re in the right place.
Let’s Take This Off Your Plate So You Can Grow What You Love
Your part-time business might have started small, but it’s becoming something real. And real businesses deserve a real tax strategy. One that’s simple, sustainable, and tailored to you.
Need help calculating your quarterly taxes?
Reach out to Insogna for personalized tax planning. We’ll build a quarterly tax payment plan that fits your business and lifestyle so you’re not just paying taxes, you’re owning them.
Because taxes shouldn’t be a barrier to your growth.
They should be part of your strategy to build something extraordinary.