Tax-Deductible Business Expenses
Like subtracting the cost of flour and sugar before calculating tax on bakery sales, it ensures you only pay taxes on your true net profit.
Definition Tax-deductible expenses (necessary expenses) refer to the essential costs incurred to run a business or earn income. Because these costs are subtracted from gross revenue when calculating taxes, you pay taxes fairly—only on the net profit you actually take home.
Why Aren't Taxes Levied on Total Revenue?
Imagine running a food stall and selling $1,000 (about 1 million KRW) worth of warm snacks in a month. On the surface, it looks like you made $1,000, but that whole amount does not go straight into your pocket. You had to buy flour, fillings, and pay for the gas to heat the grill.
If ingredients and utilities cost $600, your actual take-home profit is only $400. If tax authorities taxed the full $1,000, that would be unfair. In tax law, this essential $600 spent to generate income is called a necessary expense (or deductible business expense).
Taxes are fair only when levied on genuine net profit. That is why necessary expenses are subtracted from total revenue first, leaving only the real profit (taxable income) subject to tax.
What Kind of Spending Counts as a Deductible Expense?
Not every dollar you spend qualifies as a business expense. The most critical criterion is a direct connection to business activities. For instance, a cafe owner buying coffee beans, paying storefront rent, or paying employee wages can naturally write those off as expenses.
For a freelance designer, purchasing a work computer, buying design books, or buying coffee during a client meeting counts as an expense. However, family weekend dinners or personal shopping cannot be deducted because they are unrelated to work.
To claim an expense, you must keep valid proof of purchase. Objective records such as tax invoices, credit card receipts, or official cash receipts prove you spent the money for business, legally lowering your tax burden.
Going Deeper: What if You Don't Have Receipts?
Many small business owners and new freelancers find it tough to track every single receipt and keep detailed books. For them, tax authorities often provide pre-set industry expense rates, estimating standard costs for a given revenue level.
This is known as estimated expense rate calculation (standard expense rate). For example, if an industry has an expense rate of 70%, earning $10,000 allows a $7,000 deduction even without complete itemized receipts. However, as revenue grows, tracking actual receipts and maintaining bookkeeping usually yields far greater tax savings.
Notably, standard salaried employees do not itemize daily work expenses with individual receipts. Instead, governments apply an automatic earned income deduction (or standard deduction) based on salary brackets, providing a similar tax-reducing effect.
🤔 Common misconceptions
Any purchase made with a business credit card automatically qualifies as a deductible expense.
Even on a business card, personal expenses like family dinners or personal groceries do not qualify. Claiming them can trigger penalties and additional taxes during an audit.
🧺 Where you meet it
Necessary expenses are essential costs incurred to earn income; subtracting them from gross revenue ensures taxes apply only to genuine net profit.