Taiwan’s tax authorities have reminded calendar-year profit-making enterprises to file or pay their 2026 provisional income tax between 1 and 30 September 2026, with exemptions available for certain businesses and entities.
The Northern Region National Taxation Bureau of the Ministry of Finance announced on 25 August 2026 that profit-making enterprises using the calendar year as their accounting year must file provisional income tax returns for the 2026 fiscal year between 1 and 30 September 2026.
Similarly, the Taipei National Taxation Bureau of the Ministry of Finance reminded calendar-year profit-making enterprises on 26 August 2026 that provisional income tax for the 2026 fiscal year must be paid or the relevant provisional tax return filed between 1 and 30 September 2026.
2026 provisional income tax filing deadline: 1–30 September
The Northern Region National Taxation Bureau of the Ministry of Finance has set 1 September to 30 September 2026 as the filing window for 2026 provisional income tax returns. Qualifying enterprises can now verify identity and pay directly online through the electronic filing system using business registration credentials or credit cards.
Two filing options
Enterprises with tax obligations may file using the general method, which bases provisional tax on half the 2025 settlement declaration income tax (excluding Article 24-5, Paragraph 2 calculations). Payment alone completes the filing, unless the enterprise applies investment tax credits, administrative relief credits, or withholding tax credits—then a formal declaration with supporting documents is required.
Trial calculation declaration allows enterprises with complete accounting records or audited statements filed on time to calculate provisional tax based on first-half 2026 operating revenue (excluding Article 43-3 controlled foreign enterprise income), then apply the current tax rate.
Exemptions from filing
Enterprises exempt from provisional tax declarations include foreign entities without fixed Taiwan locations, sole proprietorships and partnerships, small-scale approved enterprises, entities exempt under tax law, newly established enterprises or those with zero 2025 liability, enterprises dissolved or merged before the deadline, and enterprises where provisional tax calculates to less than TWD 2,000. The Ministry may exempt additional enterprises as needed.
2026 provisional tax filing window
Meanwhile, the Taipei National Taxation Bureau of the Ministry of Finance requires profit-making enterprises to file provisional taxes between 1 September and 30 September 2026.
How to calculate provisional tax
Most enterprises pay half of their previous year’s income tax. Excluded from this calculation are real estate transaction income (Article 4-4) and certain taxes computed under Article 24-5, Paragraph 2. Alternatively, businesses with complete accounting records or accountant certification can calculate provisional tax using only their first six months of 2026 income, applying the current year’s tax rate. This method doesn’t include controlled foreign corporation investment income under Article 43-3.
Payment options
Enterprises can pay via the Ministry of Finance tax portal (https://www.etax.nat.gov.tw), financial institutions, ATMs, convenience stores (for amounts under TWD 30,000), or credit cards.
Who is exempt
Sole proprietorships, small businesses exempt from uniform invoices, newly established businesses, entities with zero previous-year tax liability, and those owing less than TWD 2,000 don’t need to file. Educational, cultural, and charitable organisations are also exempt, as are businesses undergoing dissolution or merger.
