Most small business owners hear “write-offs” and “estimated taxes” all the time, but still feel unsure about what they actually mean. You are not alone if you nod in conversations and then quietly wonder, “What, exactly, are estimated taxes?”
Research shows that many small business owners struggle with cash flow and financial confidence (including understanding what counts as an expense, and how much to set aside for taxes), rather than a lack of revenue alone. According to QuickBooks data, 32% of small business owners say better financial literacy would help them improve budgeting and cash flow, and 19% say it would help them better understand their taxes. Additionally, less than half of small business owners are confident they’re paying taxes correctly, which shows a direct link between uncertainty about tax basics and financial stress in business operations.
Before we go any further, let me introduce myself properly.
I’m Nicole Davis, CPA, business strategist, and Managing Partner of Conscious Accounting, serving hundreds of small businesses throughout the US. My firm’s mission is to help entrepreneurs engineer their best lives by operating financially fit businesses. Because when your numbers are strong, your decisions are stronger.
I’ve been named to the Forbes List of Top 200 CPAs in America and the Forbes List of Best-in-State CPAs. Not because I chase titles, but because I deliver results.
And I live by one simple motto: It doesn’t cost to have a good CPA. It pays.
I am partnering with Intuit QuickBooks for their Ask The Expert Series to explain “write-offs” and “estimated taxes” using something everyone understands: a lemonade stand.
Imagine you set up the best lemonade stand on the block. Bright sign. Fresh lemons. The good pebbly ice. You charge $5 a cup, and 20 neighbors show up. Cha-ching. You just made $100. That $100 is your income. It is what your business earned.
But here is what people forget. You had to buy lemons, sugar, cups, a table, and maybe even a big poster board sign so people could find you. That cost matters. So, you did not actually keep $100. Everything you bought to make the lemonade stand work is a write-off or deduction. Let’s say you spent $40 on supplies.
Simple math: $100 income minus $40 expenses equals $60 profit.
You pay taxes on the $60 that is left, not the full $100 that came in. This is one of the most basic concepts in business taxes. Income comes in, expenses go out, and the profit that remains is what gets taxed.
In real life, those numbers are tracked on your Profit and Loss Statement, which shows your business earnings (income), write-offs (expenses), and profit over a period of time. If you want a clearer breakdown of how that report works and why it matters for your business, QuickBooks has a helpful guide you can read more about here.
Now, let's talk about write-offs.
A write-off is simply a deduction that lowers the amount of income the government can tax. In business language, the rule is pretty straightforward. The expense has to be ordinary and necessary. “Ordinary” means it’s common for the kind of business you run. “Necessary” means it actually helps you operate the business or make money.
Going back to our lemonade stand example, you obviously need lemons, sugar, cups, ice, maybe a little table, and a bright sign that tells the neighborhood kids where to find you. Those things help you produce and sell lemonade, so they count as write-offs.
Without them, you don’t have a lemonade stand. You just have ambition and a pitcher.
Remember, the government does not tax every dollar that comes into your business. They tax what’s left after you pay for the things required to run it.
So, write-offs lower the income that gets taxed. They don’t magically erase taxes, but they make sure you’re paying taxes on the profit you actually keep.
A common misconception is that if you buy it using business funds or through the business, it’s a write-off. This is not true.
For instance, buying a television for your lemonade stand probably would not count as a write-off. A television is not typically needed to make or sell lemonade, so it would fail the “ordinary and necessary” test. The IRS cares about why you bought it, not how you paid for it.
Here’s another thing people misunderstand: Write-offs do not reduce your taxes dollar for dollar.
They reduce the income that gets taxed.
For example, if you spend $50 buying a cooler to keep your lemonade cold, you might only save around $13 in taxes, depending on your tax bracket. Tax brackets are simply ranges the government uses to tax income in layers instead of all at once. As your income grows, it moves through different brackets. Each bracket applies only to the income that falls within that range. For example, one portion of your income might be taxed at 10 percent, the next portion at 12 percent, and the next portion at 22 percent.
Understanding how deductions and tax brackets work together can help you make smarter financial decisions for your business. If you want to learn more about how deductions work and how tools like Business Tax AI can help identify eligible expenses, check out this QuickBooks resource on maximizing business deductions.
Now that we understand how write-offs lower your taxable income, let’s talk about what you actually owe the government.
That amount is called your tax liability. Your tax liability is the total amount of tax you are responsible for paying based on your profit after deductions. Going back to the lemonade stand example, if you earned $100 and spent $40 on supplies, your profit is $60. That $60 becomes the starting point for calculating your tax liability.
This is where owning a business and having a paycheck start to behave very differently.
When you work for someone else, taxes quietly disappear out of every paycheck before the money even hits your bank account. Your employer sends it to the IRS, and you move on with your life.
When you run your own lemonade stand, nobody is doing that for you. You collect the full $100. Which feels great… until you realize some of that money actually belongs to the government.
That’s where estimated taxes come in.
Estimated taxes are simply the payments you make throughout the year toward your tax liability so you are not hit with one giant bill later. The IRS generally expects these payments four times a year. The typical due dates are April 15, June 15, September 15, and January 15 of the following year. A good rule of thumb is to set aside 25-30% of your profit for estimated tax payments. If you want the official breakdown straight from the source, the IRS explains it here.
Write-offs and estimated taxes are not separate conversations. Write-offs determine how much of your money gets taxed. Estimated taxes determine when you pay it. One reduces the amount you owe. The other keeps the timing from wrecking your cash flow. Ignore either one and you get surprises. And not the fun kind. I’m talking about things like:
- A tax bill that makes you stare at your screen for a long time.
- IRS penalties because you didn’t pay in enough during the year.
- Realizing the money you owe has already been spent on something else.
A little organization goes a long way here. Three simple habits make this much easier.
First, separate your business and personal money. A dedicated business bank account makes tracking income and expenses much cleaner.
Second, track your expenses as you go. Those lemons, cups, software subscriptions, and marketing costs add up, and they matter when calculating your profit.
Third, set aside tax money regularly. Many business owners move a percentage of each payment they receive into a separate savings account, so quarterly tax payments are not a panic moment.
At the end of the day, your business may not actually be a lemonade stand, but the math works the same way. Money comes in. Expenses go out. Taxes apply to what is left. When you understand write-offs and estimated taxes, you stop guessing and start running your business with a lot more confidence.
