Tax authority urges assessed-method businesses to declare Q4 2025 input tax by 5 January to claim deductions.
Taiwan’s Southern Region National Tax Administration of the Ministry of Finance has reminded businesses using the assessed method for calculating business tax to declare input tax certificates for the fourth quarter of 2025 by 5 January 2026. The Q4 2025 assessed business tax will be levied in February 2026.
The Bureau explained that, under Article 25 of the Value-Added and Non-Value-Added Business Tax Act and Articles 31 and 44 of its Enforcement Rules, businesses using the assessed method for calculating business tax that purchase goods or services for business use and obtain certificates indicating business tax amounts must declare the input tax certificates for each month of the period to the competent tax authority by the 5th of January, April, July, and October. The competent authority will then allow a deduction equal to 10% of the input tax from the assessed tax (not applicable if the assessed tax does not reach the threshold).
However, input tax amounts that cannot be deducted under Article 19, Paragraph 1 of the same Act—such as purchases without valid certificates, goods or services not for main or ancillary business use, entertainment expenses, goods or services for employees’ personal use, or private passenger cars—or certificates not declared within the required period or for months outside the current period, cannot be deducted from the assessed tax.
Example: Business A, an assessed taxpayer selling small accessories, has a monthly assessed sales amount of TWD 120,000. The quarterly business tax would normally be TWD 3,600 (TWD 120,000 × 1% × 3 months). Business A obtained invoices for purchases from October to December 2025 with a total input tax of TWD 12,000. If the deduction certificates are declared to the tax authority by 5 January 2026, the Q4 2025 business tax can be reduced by TWD 1,200. Therefore, Business A would only need to pay TWD 2,400 for Q4 (TWD 3,600 − TWD 1,200).
The Bureau urged businesses using the assessed method to obtain triplicate uniform invoices or other certificates showing the business tax amount for goods or services purchased for business use and to declare them within the prescribed deadlines to avoid missing the opportunity to deduct assessed business tax.
