According to the provisions of Article 19 of Decree 123/2020/ND-CP, the issuance of replacement invoices can be applied in the following cases: (1) In the case where the seller discovers an electronic invoice, which has been assigned a tax authority code but has not been sent to the buyer, contains errors, the seller must notify the tax authority using Form 04/SS-HĐĐT in Appendix IA issued along with Decree 123/2020/ND-CP for canceling the electronic invoice with an incorrect code that has been issued and issue a new electronic invoice. The seller must sign and send it to the tax authority to get a new invoice code to replace the incorrect invoice and send it to the buyer. The tax authority will cancel the incorrect electronic invoice with the assigned code stored in the tax authority's system. (2) In the case where the electronic invoice with a tax authority code or the electronic invoice without a tax authority code has been sent to the buyer, and the buyer or seller discovers errors: The seller must issue a new electronic invoice to replace the erroneous one, except in cases where the seller and the buyer have agreed in writing before issuing the replacement invoice for the one with errors. In this case, the seller and the buyer must create a written agreement specifying the errors, after which the seller will issue a replacement electronic invoice for the one with errors. The new electronic invoice replacing the erroneous one must include the statement: "Replacement for invoice Model No... code... number... date... month... year." The seller signs the new electronic invoice that adjusts or replaces the erroneous one and then sends it to the buyer (in the case of using an electronic invoice without a tax authority code) or sends it to the tax authority for the tax authority to issue a code for the new electronic invoice to be sent to the buyer (in the case of using an electronic invoice with a tax authority code).