Family Tax Unit in Coretax: Definition and Reporting

The Directorate General of Taxes (DJP) introduced the Family Tax Unit (DUK) as part of the Coretax system effective in 2025. DUK is referenced in discussions about merging married couples’ NPWPs and issuing Income Tax Withholding (Bupot) 21 for wives.

Although PER‑7/PJ/2025 does not give an explicit definition, Article 5 treats DUK as a collection of family‑member data, including fully dependent members and a broader set. Under Article 8 of the Income Tax Law, a family is a single economic unit, so all members’ income is combined and reported by the head of household, except when spouses are legally separated, have a property‑division agreement, or the wife elects independent tax status.

Accurate DUK reporting links spouses’ tax accounts in Coretax and ensures correct PPh 21 withholding; a family member listed in one DUK cannot appear in another. Taxpayers update their DUK through the data‑change feature on the Coretax portal.