When reviewing year-end tax settlement documents, you will repeatedly encounter the terms “income deduction” and “tax credit.” Both can ultimately reduce your tax burden, but they apply at different stages and are calculated differently.
An income deduction reduces your taxable income before the tax rate is applied. A tax credit deducts a certain amount from the tax calculated after applying the tax rate. If you do not understand this distinction, you may misjudge the actual tax-saving effect based only on the amount eligible for a deduction or credit.
To understand the difference between the two deductions accurately, you first need to review the complete year-end tax settlement calculation process. This article explains where income deductions and tax credits are applied and how they affect the calculation through practical examples.
What Is the Difference Between an Income Deduction and a Tax Credit?
The main difference between an income deduction and a tax credit is what each one reduces.
- Income deduction: It reduces the taxable income used as the basis for calculating tax.
- Tax credit: It reduces the tax calculated after applying the tax rate to taxable income.
Therefore, an income deduction of 1 million won and a tax credit of 1 million won do not have the same effect. An income deduction of 1 million won reduces taxable income by 1 million won, while a tax credit of 1 million won directly reduces the calculated tax by 1 million won.
However, the entire amount you spend does not automatically become a tax credit during year-end tax settlement. The final tax credit is calculated by applying the applicable credit rate and limit to the eligible amount, so you must distinguish between the amount spent and the actual tax credit.
What Is an Income Deduction?
An income deduction reduces taxable income by subtracting a certain amount from your income before the tax rate is applied.
During year-end tax settlement, earned income is calculated by subtracting the earned income deduction from gross pay. Personal deductions, pension insurance premium deductions, special income deductions, and other income deductions are then applied to calculate taxable income.
Taxable income is the amount to which the tax rate is actually applied. When an income deduction lowers taxable income, the amount subject to the tax rate decreases, which may also reduce the calculated tax.
Common income deductions include the following:
- Personal deductions
- Pension insurance premium deductions for employee contributions to public pensions
- Special income deductions for health insurance premiums, employment insurance premiums, and housing-related expenses
- Other income deductions, including qualifying credit card spending and housing savings
Different requirements apply to each deduction, including eligibility, income conditions, spending periods, and deduction limits. Even expenses with similar names may or may not qualify depending on the individual’s circumstances.
What Is a Tax Credit?
A tax credit directly subtracts a certain amount from the tax calculated after applying the basic tax rate to taxable income.
Under the National Tax Service’s year-end tax settlement calculation structure, the final tax liability is calculated by subtracting tax reductions and tax credits from the calculated tax. The final tax liability is the income tax an employee ultimately owes after all applicable reductions and credits have been applied.
Common tax credits include the following:
- Earned income tax credit
- Child tax credit
- Pension account tax credit
- Special tax credits for insurance premiums, medical expenses, education expenses, and donations
- Monthly rent tax credit for eligible taxpayers
A tax credit does not deduct the entire amount spent from your taxes. The eligible amount is calculated for each category, and the applicable credit rate and limit are then applied. The amount you can actually claim may vary depending on your calculated tax and other tax credits.
Where Do the Two Deductions Apply in the Calculation Process?
The stages at which the two deductions apply can be simplified as follows:
- Calculate gross pay by subtracting non-taxable income from annual employment income.
- Calculate earned income by subtracting the earned income deduction from gross pay.
- Calculate taxable income by subtracting the applicable income deductions from earned income.
- Calculate the tax before credits by applying the basic tax rate to taxable income.
- Calculate the final tax liability by subtracting tax reductions and tax credits from the tax before credits.
- Compare the final tax liability with the tax already paid to calculate the refund or additional payment.
The process can be expressed using the following simplified formulas:
Taxable income = Earned income − Income deductions
Tax before credits = Tax calculated by applying the tax rate to taxable income
Final tax liability = Tax before credits − Tax reductions − Tax credits
Example: Why Similar Amounts Can Have Different Effects
The following simplified example explains where income deductions and tax credits apply in the calculation. Actual taxes must be calculated by considering progressive tax rates, deduction and credit limits, and individual eligibility requirements.
Example 1: Applying an Income Deduction of 1 Million Won
- Taxable income before the deduction: 30 million won
- Income deduction: 1 million won
- Taxable income after the deduction: 29 million won
In this case, 1 million won is not deducted directly from the tax owed. Instead, taxable income is reduced by 1 million won, and the actual tax savings depend on the tax rate applicable to that income bracket.
Example 2: Applying a Tax Credit of 150,000 Won
- Tax before the credit: 3 million won
- Applicable tax credit: 150,000 won
- Tax after the credit: 2.85 million won
If the tax credit is calculated as 150,000 won, that amount is deducted directly from the calculated tax. However, an eligible expense of 1 million won does not necessarily result in a tax credit of 1 million won.
Which Is More Beneficial: an Income Deduction or a Tax Credit?
A tax credit is relatively easy to understand because it is deducted directly from the calculated tax. In contrast, the tax-saving effect of an income deduction varies depending on taxable income and the applicable tax rate.
However, this does not mean that a tax credit is always more beneficial. Eligible amounts, credit rates, limits, income levels, dependents, and calculated taxes vary from person to person. The actual tax-saving effect should be evaluated using the complete calculation after applying every eligible deduction and credit.
The important point is that taxpayers do not arbitrarily choose which type of deduction to claim. When an expense or family relationship meets the legal requirements, either an income deduction or a tax credit applies according to the rules for that category.
How to Review the Items on Your Withholding Tax Certificate
After year-end tax settlement is complete, you can check your employment income withholding tax certificate to see where the two types of deductions were applied.
- Check your earned income.
- Check your personal deductions, special income deductions, and other income deductions.
- Check your taxable comprehensive income.
- Check the tax calculated by applying the tax rate to taxable income.
- Check your tax reductions and tax credits.
- Compare your final tax liability with the tax already paid.
To understand your final refund, you also need to review how tax is withheld from your salary. A refund is determined not only by deductions but by the difference between your final tax liability and the tax you already paid during the year.
What to Check Before Year-End Tax Settlement
- Do eligible taxpayers and dependents meet the applicable income requirements?
- Has more than one person claimed a deduction for the same dependent?
- Have you correctly distinguished income deductions from tax credits?
- Have you avoided confusing eligible expenses with the actual tax credit?
- Do the items shown in the simplified tax data actually meet the applicable requirements?
- Have you checked the deduction and credit rates and limits for the relevant tax year?
An item appearing in the year-end tax settlement simplification service does not automatically confirm that it qualifies. Employees must verify the requirements for each item and prepare additional supporting documents when necessary.
Common Misunderstandings
An Income Deduction of 1 Million Won Reduces Tax by 1 Million Won
An income deduction reduces taxable income, not the tax itself. The actual tax savings depend on the applicable tax rate.
All Eligible Expenses Are Deducted Directly from Tax
The tax credit is calculated by applying the relevant credit rate and limit to eligible expenses. The amount spent and the actual tax credit may be different.
A Large Refund Means You Received More Income Deductions and Tax Credits
The refund amount is affected not only by your final tax liability but also by the amount of tax already withheld. You should not evaluate your tax savings based solely on the size of your refund.
ConclusionConclusion
Both income deductions and tax credits can reduce your tax burden, but they apply at different stages of the calculation.
An income deduction lowers taxable income before the tax rate is applied, while a tax credit directly reduces the tax calculated after applying the tax rate. Therefore, you should not compare only the eligible amounts. You should also review how taxable income, tax before credits, and final tax liability are calculated in sequence.
Eligibility requirements and limits may vary depending on the relevant tax year and individual circumstances. When completing your year-end tax settlement, check the National Tax Service guidance for that year and review the information provided by your employer.
This article provides general financial and tax information and is not a substitute for personalized tax advice.
References
National Tax Service, Year-End Tax Settlement Calculation Method for Employment Income
National Tax Service, Special Income Deductions
National Tax Service, Special Tax Credits