From 1 July 2026: withholding PIT on wages is filed QUARTERLY only — monthly filing ends (Form 05/KK-TNCN)

A change that has just taken effect matters to every business that pays wages: from 1 July 2026, the declaration of withheld personal income tax (PIT) on salaries and wages (Form 05/KK-TNCN) is filed quarterly for all income-paying organisations — monthly filing is abolished, no longer split by company size. If you used to file 05/KK-TNCN every month, the June 2026 period is your last monthly filing; from Q3 2026 onward you file quarterly.

Before and after 1 July 2026

The key point is that the filing cadence changes, while the way you compute withheld tax is unchanged (still the progressive scale for employees on labour contracts ≥ 3 months, and a flat 10% on casual payments ≥ VND 2 million per instance).

In other words, the businesses most affected are those that used to file monthly (typically larger businesses that file VAT monthly). Small businesses already on a quarterly cadence see almost no difference — they were quarterly already.

Why the change?

This is one piece of the roll-out of the Law on Tax Administration 108/2025/QH15 (effective 1 July 2026, replacing Law 38/2019). The implementing Decree 252/2026/NĐ-CP (replacing Decree 126/2020) and Circular 89/2026/TT-BTC (replacing Circular 80/2021) all take effect on 1 July 2026. Within that, Article 22 of Circular 89/2026 sets the declaration of withheld PIT on salaries and wages to a quarterly cadence with annual finalisation — dropping the monthly filing for this item.

Quarterly deadlines

On a quarterly cadence, the deadline is the last day of the first month of the following quarter — the general quarterly deadline in Decree 252/2026/NĐ-CP, Article 10 (carried over unchanged from Law 38/2019, Article 44):

The annual PIT finalisation (Form 05/QTT-TNCN) is unchanged: still finalised yearly, due by the last day of the third month after the calendar year ends (≈ 31 March).

What monthly filers must do

1. The June 2026 period is your last monthly 05/KK-TNCN (due 20 July 2026 on the old monthly cadence).
2. From Q3 2026, combine the withholding for July, August and September 2026 into a single quarterly filing, due by 31 October 2026.
3. No change to the calculation: the withheld tax per person is computed exactly as before — you simply aggregate by quarter instead of filing each month.
4. Still pay the withheld tax on time per the quarterly filing — late payment still accrues the 0.03%/day interest charge.

Every figure carries the law

True to Kê Khai’s every figure carries the law principle, this change traces back to the primary texts on the government’s official portal:

• Quarterly PIT filing on wages from 1 Jul 2026 (monthly filing dropped): Circular 89/2026/TT-BTC, Article 22 (replacing Circular 80/2021), with the cadence detailed in Decree 252/2026/NĐ-CP (replacing Decree 126/2020), both effective 1 July 2026 — implementing the Law on Tax Administration 108/2025/QH15.
• Quarterly filing deadline (last day of the first month of the next quarter): Decree 252/2026/NĐ-CP, Article 10 — the figure carried over unchanged from Law 38/2019, Article 44.
• Periods ≤ 30 Jun 2026 keep the old cadence: Decree 126/2020/NĐ-CP (PIT cadence follows the VAT cadence) — still correct for periods before the transition.

Kê Khai already handles the transition

Kê Khai builds the 1 July 2026 boundary into its PIT-withholding path: for tax periods from 1 July 2026, the app sets the 05/KK-TNCN cadence to quarterly for every business; for periods ≤ 30 June 2026, it keeps the VAT-derived cadence — so historical periods still cite the decree that was actually in force at the time.

You can open the Kê Khai app to prepare 05/KK-TNCN on the new cadence, or read more about why every figure carries the law.