Comparing Korea’s 80%, 100% and 120% Withholding Choices
Hold the payroll inputs fixed and isolate the effect of Korea’s withholding-percentage choice. This is a timing comparison under Korean law, not a tax-saving strategy, refund guarantee or international payroll rule.
Fix the case inputs first
Use the fictional case of taxable monthly pay of 3,500,000 KRW, four eligible family members including self and two eligible children aged 8–20. Keep the supported payment date and exempt-pay setup fixed. Changing family count together with the percentage hides which change produced the difference.
1. Establish the 100% reference
Select 100% and inspect the table version, bracket and child conditions. On HomeTax use the version applying to withholding from March 1, 2026. Do not mix an older child-allowance example into that version. If the check is blocked or outside scope, stop this comparison and use the official service.
2. Change only the percentage
Repeat with 80% and 120%, recording income and local income tax separately. Rechecked against the current HomeTax version, this fictional case gives income/local tax of 2,800/280 KRW at 80% (3,080 total), 3,510/350 at 100% (3,860), and 4,210/420 at 120% (4,630). Use the displayed whole-KRW results rather than multiplying an already combined total. Per-item truncation stages can differ from a decimal-only calculation.
3. Restore the percentage actually used by payroll
Selecting 80% in this tool does not change an employer’s payroll settings. Confirm the percentage actually applied, restore it, then enter the two payslip amounts. If the real setting is unknown, it is a possible explanation, not an established cause.
4. Separate monthly deductions from final liability
A lower current deduction at 80% does not mean the final annual liability fell by that amount. Choosing 120% does not guarantee a refund or create a gain. Annual income, deductions and tax already paid still need reconciliation; this page does not project an annual refund.
Useful notes after comparison
Keep the date, taxable pay, family/child counts, version, percentage and both tax lines together for a payroll question. Do not publish a real payslip or family names. Reliefs, special schemes, bonuses and out-of-period payments are excluded; seek an official or qualified professional assessment where needed.
Try the relevant tools
These case links concern Korean law only. The salary check excludes insurance and final annual tax.
Compare a Korean withholding choiceSources and scope
Case text added October 21, 2026. Fictional inputs; Korean scope only. No professional review or personal tax advice is claimed. Read each source’s effective period and the tool’s policy status.
홈택스 근로소득 간이세액표 · 2026.03.01 이후 적용판