Korean Tax Seasons: Your Year-Round Compliance Calendar

Keeping up with taxes seems an ongoing responsibility that never goes off duty. 

Any accountant or business can relate to this as the taxation process involves monthly filing, quarterly reports, and a year-end closing scramble. In fact, it may seem like a 24/7 task, especially in South Korea, where tax duties have distinct, recurring peaks throughout the korean-tax-seasons-your-year-round-compliance-calendaryear. 

The fact is that although the tax tasks are year-long, their intensity varies. Being aware of these natural rhythms can assist you in planning better, being less stressed, and being healthier in your financial management habits. 

This guide divides the annual tax calendar in Korea into specific periods- when to be on the go and, more importantly, when to pause, look back, and look ahead.

The High Seasons: When the Pressure Is On

The Korean tax year is typically characterized by four key seasons, explained below.

Quarterly VAT Returns (The Peaks)

VAT (Bugase) is submitted four times a year. To the majority of ordinary taxpayers, these dates are not negotiable and are high-stress times.

Quarter		Filing Period	Deadline
Q1		January 1 – March 31	April 25
Q2		April 1 – June 30	July 25
Q3		July 1 – September 30	October 25 (Prepayment deadline for the second half-year for Small/General Taxpayers)
Q4		October 1 – December 31	January 25 (of the following year)

Key Activity: This is the period when all the sales data (tax invoices, card receipts) and purchase data are collected to determine the net VAT payable or refundable. July and January are particularly intense because they entail the final settlement of the half-year before.

May: Comprehensive Income Tax (The Everest)

May is the most important month for sole proprietors and the majority of individuals. This is when you must file and pay the Comprehensive Income Tax (종합소득세, Jonghap Sodukse) for the entire previous calendar year.

Key Activity: Summing up all sources of income (business, labor, financial, and so on), subtracting all expenses that have to be used, and implementing all possible tax credits. It is necessary to prepare it well in advance to avoid last-minute panic and mistakes.

March: Filing of Corporate Tax (The Summit)

In the case of corporations (법인, Beobin), the annual filing of Corporate Income Tax (법인세, Beobinse) has to be submitted. For companies with a December 31 fiscal year-end, the corporate tax return is due by March 31. Companies with different fiscal year-ends must file within three months after their respective year-end.

Key Activity: Preparing the financial statements of the company for the previous year, reconciling the accounting books with the tax legislation (tax adjustments), and filing the final corporate tax return. It is the culmination of all the bookkeeping of the year.

The Peace and Planning Seasons: The use of the Lulls.

Although the big deadlines are the ones that draw attention, the real trick to stress-free compliance is to know and take advantage of the less noisy times of the Korean tax seasons.

August - A Short Summer Calm 

Once the Value-Added Tax (VAT) is done in July, August ensures a short period of relaxation.

It is the month that has no big deadlines--no VAT, no end-of-year settlements, no income tax returns. The accountants and the business owners can now take a pause. Instead of August being your downtime, consider it your business reflection time.

How to use this time wisely:

• Review: See whether any bookkeeping entries were overlooked during the first half-year. Have you obtained receipts for all deductible expenses?

• Consult: Have a brief meeting with your tax advisor mid-year to get tips on saving taxes, such as ensuring that large expenses are classified in the right way.

• Plan: Revise your sales flow and revise your second-half business plan, including any tax lessons you have learned in the first half.

October - November - The Season of Preparation. 

Although December can be considered the start of the official rush of the year, the real preparation season starts in October and November. This is where intelligent planning can help you with the Korea tax filing schedule. In these months, you will be able to prepare financial data and implement tax-saving methods before deadlines run out.

The most important strategic activities during this time:

• Check Deductions: Check all deductible expenses systematically and make sure that there are no missing costs. Be proactive in obtaining supporting documentation for any doubtful or high expenses.

• Tax Credits Review: Review areas in which any further tax credits (such as research and development or employment support) can still be claimed before the end of the year, as closing makes it hard to make adjustments.

• Limit Pre-review: Pre-review annual limits on deductible spending on individuals (medical, donations, pensions, etc.) to maximize utilization.

• Clean-up Bookkeeping: Make sure that all bookkeeping and documentation of the third quarter is done and correct before the final push to Q4.

Late February - Early March - The Quiet Recovery. 

The period between the February payroll year-end payroll filings(e.g., year-end settlement of employment income tax and social insurance) and the May Comprehensive Income Tax season is a short recovery period. However, it is high time to review the previous year's performance and strategize for the future to make sure that your tax calendar for Korea is ready for the following year.

Concentrate on analysis and vision:

• Financial Review: Read the financial closing report of last year carefully. Look for abnormalities, unforeseen tax bills, or missed opportunities.

• NTS Data Check: Compare the data that was reported to the National Tax Service (NTS) by your clients or vendors and compare it with your own records.

• Strategic Planning: Develop a spending and investment plan based on your business objectives in the current year, considering the effect of different activities (e.g., purchase of equipment, hiring) on your tax burden in the next March/May.

When you have your bookkeeping organized at the beginning of March, your May tax filing will be much easier, and you will have more time to develop effective year-end tax plans before the next cycle starts.

J&J Korea Insight: Mastering the Tax Rhythm

Many entrepreneurs ask, “Is there ever a quiet time in tax?”

Yes, but you have to know the rhythm.

Tax work has its own pulse--months of hard work with valuable pauses. The difference between a perpetually stressed business owner and a calmly compliant one often boils down to how they use those quiet moments.

Recognizing these patterns helps business owners: 

Be Proactive: 

Instead of reacting to a deadline on the 24th, you’re gathering data in the quiet weeks of the preceding month.

Manage Cash Flow: 

By completing preliminary tax calculations in November, you can forecast your tax liability and set aside cash, avoiding a surprise payment shock in March or May.

Maximize Deductions: 

It is best to use the months of August or October to go through the previous months so that you do not miss any important expense receipts and maximize your tax savings.

You do not need to be anxious about your Korean tax returns throughout the year. With this compliance calendar, you can plan your business activities to align with the natural rhythm of the NTS deadlines. This is the proactive strategy that will reduce stress and ensure a healthy financial position for your business in Korea.

At J&J Korea, we make the most of these windows--keeping your business up to date, efficient, and prepared to meet all financial seasons ahead. Are you planning to begin your strategic tax preparation? Get in touch now for a year-round tax consultation.