How does tax treatment change based on an IT developer's work arrangement?
IT developers may be classified under business income or employment income depending on whether they're a freelancer (3.3% withholding), semi-freelancer, on-site, or remote — and that classification changes which tax rate applies, what expenses are recognized, and how the four major social insurances are handled. In particular, whether you qualify as a "teukgo" (specially employed worker) and which business-registration path you take (freelancer code vs. software development code) can create a large gap in your actual tax burden, so it's important to get an accurate read on your real working arrangement and build a tax strategy around it.
IT & developer tax work is different from standard bookkeeping
Overseas source income
Foreign-currency conversion and zero-rate VAT treatment for income from app stores, Google AdSense, and overseas clients (Upwork, etc.)
R&D tax credit
R&D personnel cost tax credits, links to venture business certification, and corporate/registration tax reductions
Income classification by work arrangement
Income filing and expense design tailored to your actual contract and work style — freelance, semi-freelance, on-site, or remote
Tax Guides by Role
From frontend to embedded systems to planning and design — check the income structure and expense items specific to your role
Web & App Development
Frontend Developer
You're devoted to every 1px — we'll track every 1 won of your expenses with the same devotion
Backend Developer
You stay up for 3am outage alerts — you don't need to stay up for tax season too
Full-Stack Developer
You handle frontend and backend solo — let us handle your income filing in a single pass too
App Developer (iOS & Android)
App Store rejections may be scary, but filing your in-app purchase revenue doesn't have to be
Data & AI
AI & Machine Learning Engineer
Train your models overnight — we'll study the tax code for you
Data Engineer
Your pipelines run clean — let us keep your income flow just as clean
Data Scientist
You extract insight from raw numbers — we'll extract insight from your taxes
Data Analyst
You dissect every metric down to the decimal — let us dissect your taxes instead
Infrastructure & Security
Cloud & DevOps Engineer
You monitor infrastructure around the clock — you don't need to watch your taxes alone too
Systems & Network Engineer
You're always on the road between client sites — let us handle the vehicle-expense math
Security Engineer
You catch every vulnerability with a hawk's eye — tax-saving opportunities are easy to miss by comparison
Other Specialties
Planning, Architecture & Design
UI/UX Designer
You design user experience with painstaking care — let us design your income with the same care
IT Planner & PM
You manage the schedule and the budget — now let us manage your taxes too
Database Administrator (DBA)
You keep data integrity airtight — we'll make sure nothing ever slips through your filing
Systems Architect
Like a scalable system, a tax structure designed ahead of time gives you real peace of mind
Operations, Support & Consulting
Maintenance Developer
You fix outages overnight — it's smarter to get ahead of taxes before they break too
Technical Support & Help Desk
You handle customer questions with endless patience — hand your tax questions to us instead
QA & Test Engineer
You catch every bug with precision — we'll catch your filing errors before they ship
IT Consultant
You propose strategy to your clients — let us propose the tax strategy for you
What Kind of Developer Are You?
Even under the same title of "developer," your contract type completely changes your income classification, four-major-insurance status, and how you file taxes
Freelance Developer
A fully independent contractor not tied to any single company, taking on project-by-project service contracts with multiple clients
- 3.3% withholding on business income, or business registration
- Regional subscriber for the four major insurances — often a heavy health-insurance burden
- Can take on multiple clients at once, with wide latitude for expense deductions
- Software engineers must enroll in workers' compensation insurance as "teukgo" workers
Semi-Freelance (Dispatched) Developer
A full-time employee of an SI or staffing firm under a standard employment contract, but dispatched project-by-project to work on-site at various client companies
- Year-end settlement and withholding handled as employment income by your employer
- Four major insurances are enrolled normally through your employer
- Side income from lecturing or side projects requires a separate filing
On-Site Developer
Commutes to and works at a client's premises, but is typically contracted as a freelancer (contracted service/entrustment) rather than an employee
- Files 3.3% business income; home-office expenses are difficult to have recognized
- Because the reality resembles employment, disguised-subcontracting risk exists
- Expense design centers on documented out-of-pocket costs like equipment and phone bills
- Subject to mandatory teukgo workers' compensation insurance, though client non-filing is common
Remote (Work-From-Home) Developer
Works remotely from home or a personal office. Commonly juggles multiple domestic and overseas clients, often through overseas outsourcing platforms
- Can allocate and expense a portion of home-office rent, maintenance fees, and internet costs
- Overseas client income should be reviewed for zero-rate VAT treatment
- Managing multiple income sources makes revenue tracking and bookkeeping relatively complex
Tax Comparison by Work Arrangement
| Category | Freelancer | Semi-Freelance (Dispatched) | On-Site Developer | Remote (Work-From-Home) |
|---|---|---|---|---|
| Income classification | Business income | Employment income | Business income | Business income |
| Withholding | 3.3% | Employment income withholding table | 3.3% | 3.3% or as a business |
| 4 major insurances | Regional subscriber (self-paid) | Workplace subscriber (employer covers a share) | Regional subscriber (self-paid) | Regional subscriber (self-paid) |
| Workers' comp (teukgo) | Mandatory enrollment | N/A (covered by standard employee workers' comp) | Mandatory enrollment (non-filing by clients is common) | Mandatory enrollment |
| Tax filing | Comprehensive income tax (May) | Year-end settlement + comprehensive income tax if side income exists | Comprehensive income tax (May) | Comprehensive income tax (May) + VAT |
| Expense deductions | Relatively flexible | N/A (employment income deduction applies instead) | Limited (mostly out-of-pocket costs) | Home-office expenses can be allocated |
| Main risk | Missing the taxation-type conversion when revenue spikes | Failing to report side income | Disguised subcontracting / quasi-employee issues | Failing to meet zero-rate VAT requirements on overseas income |
Business Registration: Personal-Services Code or Development Industry Code?
Even for the same developer, the industry code and taxation type you choose completely change when bookkeeping obligations kick in and whether you qualify for tax reductions
Why the industry code matters most
Decide your business address and taxation type in advance too
Check whether you're inside the Overconcentration Control Region first
The startup SME tax reduction under the Restriction of Special Taxation Act varies significantly by reduction rate depending on whether your business address is inside or outside the Overconcentration Control Region of the Seoul metropolitan area. Since you must enter your business address along with your trade name and contact info on the business registration application, review this in advance if you want to maximize your reduction.
Register as a general taxpayer if you need to issue tax invoices
A recent tax law change lets simplified taxpayers (under 80 million KRW in annual revenue) issue tax invoices too, but your taxation type can change frequently as revenue fluctuates, and some clients are reluctant to work with simplified taxpayers who can't claim input VAT credits. If issuing tax invoices is your goal, it's safer to register as a general taxpayer from the start.
Industry codes, double-entry bookkeeping thresholds, and reduction requirements can change with tax law revisions. Confirm the exact code and taxation type through an individual consultation before registering a business.
Did you know IT developers can be a "teukgo"?
Software engineers are legally classified as specially employed workers (service providers). Separate from taxes, there are separate workers' compensation and employment insurance obligations
Software engineers must enroll in workers' compensation insurance
Starting July 1, 2021, freelance developers who qualify as software engineers under the Software Industry Promotion Act and provide labor without employing others were classified as service providers ("teukgo") under the Industrial Accident Compensation Insurance Act and became subject to mandatory workers' compensation enrollment.
Especially important to check if you're an on-site developer or SI freelancer
It's common for client companies (including agencies) to fail to fulfill their workers' compensation and employment insurance filing obligations, so payments arrive with only the 3.3% income tax withheld and no insurance premium ever deducted. This is a filing failure on the part of the contracting business, but it can directly disadvantage the developer — for example, being unable to claim unemployment benefits when changing jobs, or compensation in the event of a workplace injury.
A separate matter from tax filing, but worth checking together
Workers' compensation and employment insurance premiums fall under social insurance rather than necessary expenses or income deductions, but they directly affect your withholding records, take-home pay, and whether you're classified as a regional subscriber for the four major insurances. It's safer to review your insurance enrollment status alongside your income filing during a tax consultation.
How IT Skill Grade (Job Rate) Connects to Your Taxes
As your day rate rises, your tax structure needs to change with it — a savings roadmap by job rate
The "junior/mid/senior/principal" grading system was abolished in 2012
Terms like "principal-grade developer" are still used out of habit in SI contracts, but since 2019 the official rate-setting standard has shifted to the average wage by role under the IT Job Competency Framework (ITSQF). It's published annually by the Korea AI & Software Industry Association (formerly KOSA) after a wage survey, and is widely used as the benchmark for public-sector fee calculations and SI/SM contract rate negotiations.
| Role (per ITSQF) | 2026 average daily wage | Estimated annual revenue at 200 working days | Key tax-saving checkpoints |
|---|---|---|---|
| IT Architect | 541,000 KRW | ~108.2M KRW | Excluded from simplified taxation, mandatory double-entry bookkeeping — review incorporation |
| Systems Operator (incl. DB) | 519,469 KRW | ~103.89M KRW | Exceeds simplified-taxation threshold; eligible for business-vehicle special rules |
| Information Security Specialist | 507,887 KRW | ~101.58M KRW | Near or over the simplified-taxation threshold; consider spreading income timing |
| IT PM | 492,039 KRW | ~98.41M KRW | Approaching mandatory double-entry bookkeeping; re-check Nolan Umbrella Fund cap |
| Application Developer (average) | 378,000 KRW | ~75.6M KRW | On the edge of the double-entry bookkeeping threshold; reconsider business registration |
| IT Tester | 197,714 KRW | ~39.54M KRW | Use the simplified expense ratio; start with basic savings via the Nolan Umbrella Fund |
Based on the 2025 Software Engineer Wage Survey (applied for 2026, published by the Korea AI & Software Industry Association). This is a reference simulation assuming 200 working days per year and may vary depending on actual contract terms.
Experience and certifications drive your rate, and your rate drives your tax structure
National technical certifications like the Engineer Information Processing or Professional Engineer Information Processing credentials, and career records verified through the Software Engineer Career Management System, are the basis for rate negotiations. As your rate rises, your revenue scale grows with it, so you should redesign your business form and taxation type around the timing of each certification.
New rules apply every time you cross a revenue threshold
You need to know in advance when you'll cross the simplified-taxation exclusion threshold (104 million KRW), the double-entry bookkeeping conversion threshold (75 million KRW for service and personal-services businesses), and the top comprehensive income tax bracket (45% above 1 billion KRW in taxable income, with the 24% sixth bracket starting at 50 million KRW) so you can respond without penalty surcharges.
The higher your day rate, the earlier you should consider incorporating
Roles with a high average daily wage, like IT architects and information security specialists, approach the top individual tax bracket with as little as 200 working days a year. Reviewing corporate tax rates (9–24%) alongside your compensation and dividend structure as a representative can significantly lower your real tax burden.
What's Included in Our IT & Developer Tax Service
Key Tax-Saving Strategies for Developers & IT Companies
Use the Nolan Umbrella Fund
Solo developers, freelancers, and on-site developers alike can claim an income deduction of 2 to 6 million KRW (2026 tiers: 6M under 40M KRW in business income, 2M above 100M KRW)
Review incorporation timing
When AI tools rapidly scale up your revenue, converting to a corporation can optimize your tax rate and four-major-insurance structure
Youth startup tax benefits
Take advantage of the youth startup SME tax reduction and early-stage corporate/income tax reductions
Tax pitfalls specific to IT
Overseas platform settlement income can lead to VAT overpayment if you miss the currency-conversion timing or the zero-rate VAT requirements. On-site developers often only get out-of-pocket costs recognized as expenses, and omitted side income (side projects, lectures, AdSense) for semi-freelance or full-time developers can lead to penalty surcharges on the following year's comprehensive income tax.
In the Age of AI, Developer Income and Taxes Are Changing
As AI tools like ChatGPT, Copilot, and Cursor become part of everyday work, developers' income structures and tax risks are shifting right along with them
AI tool subscriptions are necessary expenses too
Subscription fees for AI tools used in development — ChatGPT Plus, GitHub Copilot, Cursor Pro, Claude Pro, API credits, and more — can be treated as necessary expenses once business relevance is established. Since most are billed by overseas providers with no tax invoice, you can't claim the VAT input credit, but you can keep your overseas card statements as documentation and reflect them as expenses when filing comprehensive income tax.
A productivity surge means a revenue surge — don't miss your taxation-type conversion
Thanks to AI tools, more solo developers are running multiple projects at once and growing revenue rapidly. There's a rising number of cases where developers cross the simplified-taxation threshold, or enter a revenue bracket where incorporating would be advantageous, without realizing it and end up paying penalty surcharges — so it's important to check your revenue trend periodically.
Even a weekend vibe-coding side project must be reported
Revenue from a no-code SaaS product, app, or Chrome extension you built over a weekend using AI still needs to be reported as business or other income. If you're a semi-freelance or full-time developer, you need to check whether it's subject to the May comprehensive income tax filing, separate from your primary employment income.
Using AI doesn't automatically qualify you for the R&D tax credit
The R&D and human resource development tax credit is judged based on genuine research and development activity and personnel costs. AI tool subscription spending alone often doesn't meet the requirements, so rather than overpromising savings, we'll help you accurately identify whether you actually qualify.
IT Freelancer Necessary Expenses — Exactly Where's the Line?
Guessing is risky. Here's a clear breakdown based on the Income Tax Act and National Tax Service standards
4 criteria for judging necessary expenses
Your industry code determines your expense ratio
Software development freelancer — industry code 940926
This is the code that applies when you provide development and maintenance services as a software engineer under the Software Industry Promotion Act. The simplified expense ratio is 64.1% for revenue up to 40 million KRW and 49.7% for the amount above that, while the standard expense ratio is 17.0%.
Registering the wrong industry code changes your tax
Registering under a different code, such as other self-employment (940909), changes the expense ratio itself and can increase your tax burden. Depending on your revenue and expense structure, the documentation-based standard expense ratio or double-entry bookkeeping is often more favorable than the simplified expense ratio, so it's worth reviewing together.
Sole proprietors can claim the R&D tax credit too, but there's a threshold
To claim the R&D and human resource development tax credit, you need recognition as an in-house R&D center or a dedicated R&D department from the Korea Industrial Technology Association (KOITA), and at least one researcher dedicated full-time to R&D. Personnel who split their time between development and sales/management are excluded from the credit, so it's important to confirm the requirements precisely before applying.
Supplies and Vehicle Costs: How IT Roles Should Handle Them
Equipment supplies and vehicle travel — easy to overlook, but recurring expense items every year
Scope of recognized supply expenses
Vehicle costs: the rules differ by business form
Small freelancers can allocate by business-use share
If you work under 3.3% without business registration, or qualify as a simplified-bookkeeping filer due to smaller revenue, the special rules for business-use passenger vehicles don't apply. You can allocate fuel, insurance, auto tax, and repair costs by your actual business-use ratio and reflect them as necessary expenses — it's safer to keep records like a trip log to support your usage ratio.
Once you become a double-entry bookkeeping obligor, caps apply
Once your revenue reaches 75 million KRW for service businesses or you're classified as a professional, you become a double-entry bookkeeping obligor and the special rules for business-use vehicles apply. Depreciation (including lease/rental payments) is capped at 8 million KRW a year, and the total cap including fuel and insurance is 15 million KRW a year — keeping a driving log lets you claim the business-use portion with no cap.
Stronger penalties for not carrying business-use-only auto insurance
Starting with the 2026 tax year, the requirement to carry business-use-only auto insurance expands to all double-entry bookkeeping obligors, and if you own two or more vehicles, related costs for any vehicle beyond the first without this coverage will be fully disallowed as a necessary expense (up from 50% recognition previously). Roles that travel between multiple client sites — on-site developers, DBAs, systems/network engineers, security engineers — should organize their vehicle-expense documentation ahead of time.
From Consultation to Filing: Our Process
Assess your work arrangement
Confirm whether your actual contract and work style is freelance, semi-freelance, on-site, or remote, and design the right filing structure
Review your income and expense structure
Identify every income source, including overseas revenue, AI tool subscriptions, and side-project income
Decide your business form and taxation type
Propose the optimal option for your revenue scale — staying a freelancer, registering a business, or incorporating
Monthly bookkeeping and ongoing tax-saving review
Continuously monitor taxation-type conversion timing as revenue trends and savings items like the R&D tax credit
Frequently Asked Questions
Related Articles
3 Taxes Every Solo & Freelance Developer Needs to Know
The key points of a developer's income structure, explained.
Overseas SaaS & Cloud Subscriptions: The Complete VAT and Expense Guide
How to handle subscription fees for tools like ChatGPT, Notion, and AWS.
The R&D Tax Credit and Venture Certification Benefits
From in-house R&D center recognition requirements to calculating the tax credit.
Choosing an Industry Code and Business Registration Requirements
The standards for choosing the industry code that benefits a developer most.
General vs. Simplified Taxpayer: Which Is Better?
The criteria for choosing your taxation type at business registration.
How to Get Your 3.3% Refund — The Complete Freelancer Withholding Guide
The mechanics of the 3.3% refund for on-site and semi-freelance developers.
If You're a Developer, You Know These Moments
Committing like you're planting grass, sighing at legacy code, explaining a timeline to a non-developer. We'll debug your taxes with the same precision
Planting Grass on GitHub Today, Too
Just like a daily commit fills in your GitHub grass, monthly bookkeeping fills in your income record without a single gap. Skip a day and it shows — on the grass and in the books alike.
The Legacy Code You're Afraid to Touch
Like that code you swore not to touch because "it works, so leave it alone" — expenses left unattended for years still aren't too late to fix. We'll refactor the deductions you've been missing.
Tired of "That'll Be Quick, Right?"
Explaining a timeline to a non-developer is exhausting — understanding tax jargon is right up there with it. We'll break down complicated tax law so even a developer gets it in one pass.
Worried Your Experience Is Going Stale
If your years of experience keep piling up while you worry they're not actually building real skill, at least let us make sure your tax strategy never goes stale, even while you build your career on your own terms.
Debug Line by Line, File Taxes All at Once
The same persistence it takes to comb through logs all night for one bug is exactly what it takes to hunt down missed expenses and deductions. We've already been doing that debugging for you.
Commit & Push — Don't Procrastinate on Filing Either
Just like a commit sitting only on your local machine does nothing for anyone, putting off your filing just comes back as a penalty surcharge. Commit and push on time, and filing on time is the surest tax saving there is.