Korea's Deemed Expense Rates: Simple vs. Standard
It is an official tax chart where the government estimates, 'Businesses in this industry probably spent around this percentage,' when you could not track every single receipt.
Definition Simple and standard expense rates are statutory percentage benchmarks used by Korea's National Tax Service to estimate deductible business expenses for self-employed individuals and freelancers who did not keep detailed accounting books.
How You Can File Taxes Even Without Receipts
When running a business or freelancing, you pay income tax on your net profit—total revenue minus your necessary business expenses. But for a beginner, a micro-business owner, or a busy freelancer, collecting every receipt and keeping formal accounting books can feel overwhelming.
That is why the tax service uses pre-compiled industry benchmarks: 'Typically, businesses in this sector spend about X% of their revenue on operational costs.' Even if you lack accounting records, the government estimates reasonable expenses so you do not face unfair tax penalties. This method of calculating taxes through estimation rather than real ledgers is called an estimated or deemed filing (*chugye singo*).
The official percentage the government uses to calculate these estimated costs is the expense rate (*gyeongbiyul*). Thanks to this rule, small business owners who failed to keep books can easily deduct costs based on government-set expense ratios without submitting stacks of paperwork.
Without this system, first-time entrepreneurs without receipts would have their entire revenue taxed as pure profit, resulting in crushing tax bills. These expense rates act as a practical tax safety net to ease the administrative burden on beginners.
The Critical Difference: Simple vs. Standard Rates
Depending on annual revenue, taxpayers fall into one of two tiers: the Simple Expense Rate (*dansun gyeongbiyul*) or the Standard Expense Rate (*gijun gyeongbiyul*). The Simple Expense Rate is a generous perk for beginners and small earners below a statutory threshold. The tax authority simply assumes 60% to 80% of your total revenue was spent on running your business, granting deductions without demanding any receipts.
However, once your business grows and your annual income crosses the statutory line, you get bumped to the Standard Expense Rate. Under this tier, the automatic flat deduction plummets to just 10% to 20%. To deduct the rest of your business expenses, you must prove three major expense categories with valid receipts.
These three essential expenses are raw materials/inventory purchases (*maeip biyong*), rent for your business premises (*imcharyo*), and payroll/labor costs (*ingeonbi*). If you do not possess valid documentation like tax invoices or payroll slips for these three items, you lose those deductions completely.
In short, the Simple Expense Rate is a forgiving system that automatically writes off most revenue without receipts, while the Standard Expense Rate is strict—deducting very little unless you bring verifiable proof of your primary operating costs.
Going Deeper: Why Bookkeeping Becomes Vital as Sales Grow
Just because you enjoyed low taxes under the Simple Expense Rate in your first year does not mean it will last. The moment your annual revenue exceeds the threshold by even a single won, the National Tax Service automatically shifts you to the Standard Expense Rate.
If you continue neglecting receipts and bookkeeping after crossing this threshold, you face immediate trouble. Because the baseline deduction rate is so meager, the tax authority may compute a massive taxable income even if you ran at a real deficit, triggering a shockingly heavy tax bomb.
On top of that, if a business above a certain revenue threshold files by estimation without books, the tax office imposes an additional penalty tax for failure to keep records (*mugijang gasanse*). With deductions slashed and penalties tacked on, your tax liability can double or triple.
Therefore, as your revenue grows, you must check your assigned expense rate bracket on the tax portal (Hometax). Keeping daily financial records—via simplified or double-entry bookkeeping—is the only reliable and safe way to protect yourself and minimize your taxes.
🤔 Common misconceptions
You can always cut your taxes dramatically through expense rate deduction without ever keeping receipts.
The generous receipt-free deduction applies only to small earners under the Simple Expense Rate. Once your income qualifies you for the Standard Expense Rate, failing to keep receipts can cause your tax bill to surge.
🧺 Where you meet it
Deemed expense rates are government-set ratios used to estimate business costs when no bookkeeping exists; the Simple Expense Rate offers generous automatic deductions for small earners, while the Standard Expense Rate offers minimal flat deductions and requires proof for major expenses.