Japan Freelancer — 確定申告 (Kakutei Shinkoku) Self-Employed Return

Establish the taxpayer's residency category (permanent resident, non-permanent resident, or non-resident), confirm they are an individual sole proprietor (個人事業主) filing 事業所得, and rule out out-of-scope situations such as corporate entities, non-residents, or cryptocurrency/real-estate capital gains. Confirm the tax year is the prior calendar year (1 January – 31 December).

Determine whether the taxpayer holds a current 青色申告承認申請書 (Form 144) approval for the target year — the application must have been submitted by 15 March of that year. Confirm bookkeeping method (double-entry 複式簿記 or simplified 簡易簿記) and intended filing channel (e-Tax or paper), as these drive the 青色申告特別控除 deduction amount (JPY 650,000 for double-entry + e-Tax; JPY 550,000 for double-entry + paper; JPY 100,000 for simplified; JPY 0 for white return).

Collect all bank statements (三菱UFJ, みずほ, 楽天銀行, ゆうちょ, SBI Sumishin, SMBC, etc.) and identify all 振込入金 credits as 事業収入. Gross up any amounts received net of 源泉徴収 (10.21% withholding by corporate clients on professional fees). Reconcile gross revenue against 支払調書 (payment records) issued by withholding clients. Confirm whether the taxpayer is registered for consumption tax (消費税) — if annual revenue exceeded JPY 10,000,000 in either of the two prior years, registration may be mandatory.

Classify all business debits from bank statements and credit card records into the standard 必要経費 categories: 地代家賃, 水道光熱費, 通信費, 旅費交通費, 接待交際費, 広告宣伝費, 消耗品費, 減価償却費, 外注工賃. Apply home-office apportionment (家事按分) for mixed-use expenses such as rent, utilities, and internet — NTA accepts floor-area or time-based ratios typically in the 20–50% range. Identify assets costing JPY 100,000–299,999 requiring depreciation treatment, and blue-return assets under JPY 300,000 eligible for immediate expensing (subject to JPY 3,000,000 aggregate annual cap).

Compile all personal income deductions (所得控除) that reduce taxable income below the business-income line. Key items: 社会保険料控除 — full national pension (国民年金 JPY 16,980/month in 2025) and national health insurance (国民健康保険) premiums paid; 小規模企業共済等掛金控除 — iDeCo and small enterprise mutual aid (小規模企業共済) contributions (fully deductible); 基礎控除 (basic deduction JPY 580,000–950,000 depending on income tier under 2025 temporary enhancement); life insurance, spouse, and dependent deductions as applicable.

Compute taxable income (課税所得金額) by rounding down to the nearest JPY 1,000, apply the progressive national income tax brackets, add the 2.1% reconstruction special income tax (復興特別所得税), subtract withholding tax credits (源泉徴収税額), and account for any 予定納税 (estimated tax) instalments already paid in July and November. Determine the net amount payable or refundable by 15 March. Flag if prior-year national tax exceeded JPY 150,000, triggering 予定納税 obligations for the coming year.

Assemble the complete 確定申告 package: 申告書B (first and second pages), 青色申告決算書 or 収支内訳書, asset register, and any required attachments (控除証明書, 支払調書 copies). Submit via e-Tax by 15 March. Retain all source records for 7 years (青色申告) or 5 years (白色申告). Remind the client about 住民税 (resident tax) assessment — the municipality will issue a notice based on the filed return, with quarterly payments starting in June.