1. Key Amendments

- Amendments to tax refund procedures and forms: The tax authority updates the procedures for processing tax refunds and overpayments for households and individual businesses, particularly clarifying the type of declaration to be used as the dossier for requesting a refund of overpaid personal income tax for taxpayers subject to the flat-rate tax method. 

(Legal basis: Article 5.2 of Circular No. 18/2026/TT-BTC (as amended and supplemented by Article 2 of Circular No. 50/2026/TT-BTC)).

- Wholesale replacement of key declaration forms: The new regulation abolishes all old declaration forms and replaces them entirely with a new set of forms for activities such as revenue notification, business household tax declaration, and real estate rental tax declaration. Accordingly, Form No. 01/TKN-CNKD, Form No. 01/CNKD, Form No. 01/BĐS, and Form No. 02/BK-KTBĐS issued under Circular No. 18/2026/TT-BTC are replaced by Form No. 01/TKN-CNKD, Form No. 01/CNKD, Form No. 01/BĐS, and Form No. 02/BK-KTBĐS issued under Circular No. 50/2026/TT-BTC. (Legal basis: Article 3 of Circular No. 50/2026/TT-BTC).

- Addition of a deadline for bank account/e-wallet declaration: State authorities have set a mandatory deadline for small-scale business households/individuals (with annual revenue of VND 1 billion or less) to submit a notification of their payment accounts to the tax authority for cash flow management purposes, no later than July 31, 2026. 

(Legal basis: Article 4.2 of Circular No. 50/2026/TT-BTC).

2. Most Significant Impacts

 Circular No. 50/2026/TT-BTC (effective from May 13, 2026) directly impacts the compliance activities of millions of business households, retail chains, e-commerce traders, and accounting-tax service providers. The replacement of a series of declaration forms and the imposition of a deadline for updating bank account/e-wallet information indicate that the tax authority is tightening revenue management, strengthening cross-referencing of digital payment data with electronic invoices and self-declared revenue. Concurrently, this regulation also indirectly affects enterprises cooperating with households/individuals, requiring them to carefully verify the account details and tax identification numbers of their partners to ensure that payments are recognized as valid deductible expenses.

3. Legal Consequences of Non-Compliance

- Rejection of dossiers and delayed processing: If old forms (Form 01/TKN-CNKD, 01/CNKD, 01/BĐS, etc.) are still used for declarations, revenue notifications, or tax refund applications, the dossier will be rejected and returned by the tax authority, requiring the enterprise/individual to redo the entire process from the beginning.

- Risk of data discrepancies and payment violations: Failure by business households to update their bank accounts or e-wallets before July 31, 2026, will increase the risk of data discrepancies in tax management records and affect the validity of payment transactions.

- Risk of expense disallowance for partner enterprises: If an enterprise transfers funds for goods/services to an e-wallet or personal account that has not been declared by the business household to the tax authority, such expenses risk being disallowed for corporate income tax finalization purposes.

4. Practical Scenarios

- Example 1: An individual livestream selling goods on TikTok Shop or Shopee with annual revenue of VND 800 million in 2025 (belonging to the under-VND 1-billion group). Previously, they received payments directly into a personal bank account or Momo e-wallet without declaration. Under Circular No. 50, this individual is required to submit supplementary Form No. 01/BK-STK to notify these account numbers/e-wallet IDs to the tax authority no later than July 31, 2026. The tax authority will use this data to cross-reference actual cash flow against declared revenue.

- Example 2: A business household owner leasing a row of motel rooms or commercial property (required to declare tax using Form 01/BĐS). If, by the June 2026 tax filing period, the accountant still prints and uses the old Form 01/BĐS file from Circular No. 18, the dossier submitted to the Tax Sub-department will be rejected. The landlord or tax agent staff must review and use the new Form 01/BĐS issued under Circular No. 50/2026/TT-BTC for the tax filing process to be completed.