Create Adjustment Invoice API

What is an adjustment invoice?

An adjustment invoice is issued when an e-invoice that has already been issued and accepted by the tax authority turns out to need a correction. An adjustment invoice does not replace or void the original invoice. The original stays in force, and the adjustment records only the difference or the information being corrected.

For example: the original invoice is 10,000,000 VND but the correct amount is 11,000,000 VND. You issue an increase adjustment of 1,000,000 VND - the difference that needs adjusting, not the whole invoice again.

Origin invoice requirements

The origin invoice is identified by original_invoice_reference_code (the reference_code of a previously created invoice, under the same provider_account_id).

The origin invoice must:

• Have been issued successfully and accepted by the tax authority. Draft or in-progress invoices cannot be adjusted.
• Be a new invoice, a replacement invoice or an already-adjusted invoice.
• Not have been replaced or cancelled.

An invoice that has already been adjusted can be adjusted again, many times.

Supported adjustment kinds

The adjustment_type parameter picks the kind of adjustment invoice:

• increase - increase adjustment
• decrease - decrease adjustment
• combined - increase and decrease on the same invoice
• info - information adjustment, carries no change in money

How to enter line items for each kind is covered under Adjustment Types (adjustment_type) below.

How it works in the SePay eInvoice API

POST v1/invoices/adjust takes original_invoice_reference_code, the adjustment kind and the lines to adjust.

The API returns a tracking_code as soon as it accepts the request. Signing and filing the invoice with the tax authority are processed asynchronously. Use the tracking_code with the invoice status tracking API to follow the status and get the final result.

An invoice can be adjusted many times.

API Endpoint

API Request

API Response

{
  "success": true,
  "data": {
    "tracking_code": "5c2d9e4b-7d96-11f1-aef4-52c7e9b4f41b",
    "tracking_url": "https://einvoice-api.sepay.vn/v1/invoices/adjust/check/5c2d9e4b-7d96-11f1-aef4-52c7e9b4f41b",
    "message": "Đã tạo yêu cầu xuất hóa đơn điều chỉnh"
  }
}

Error Handling

Adjustment Types (adjustment_type)

Buyer Information (buyer)

• For increase/decrease/combined: buyer is optional. When omitted, the origin invoice's full buyer info is reused.
• For info: buyer is required - it is the corrected information itself (e.g. the new address, the correct tax code).

Usage Notes

• payment_method is optional - when omitted, the origin invoice's payment method is reused.
• issued_date is optional and must always be today (defaults to the API call time).
• For increase/decrease/combined: at least one line with a non-zero value is required. All-zero goods lines are skipped automatically.
• For info: at least one content line describing the corrected information is required (typically a note line, line_type=4), and totals must equal 0.
• discount_tax (discount %) is never negative - to decrease a discount, send a negative discount_amount directly.
• is_draft=true creates a draft - issue it later via the issue invoice API using the draft's reference_code. is_draft=false creates and issues immediately.
• After a successful request, use tracking_url to call the invoice status tracking API - always poll until a terminal result (success or failure).

Sample Code

curl --request POST \
  --url https://einvoice-api.sepay.vn/v1/invoices/adjust \
  --header 'Authorization: Bearer REPLACE_BEARER_TOKEN' \
  --header 'content-type: application/json' \
  --data '{"provider_account_id":"0aea3134-da40-11f0-aef4-52c7e9b4f41b","original_invoice_reference_code":"084e179d-d95a-11f0-aef4-52c7e9b4f41b","adjustment_type":"increase","issued_date":"2026-07-30 00:00:00","reference_code":"5c2d9e4b-7d96-11f1-aef4-52c7e9b4f41b","payment_method":"TM/CK","is_draft":false,"buyer":{"type":"personal","name":"Công ty TNHH ABC","legal_name":"CÔNG TY CỔ PHẦN ABC","tax_code":"0123456789","address":"123 Đường ABC, Quận 1, TP.HCM","email":"contact@abc.com","phone":"0901234567","buyer_code":"KH-001","national_id":"001234567890"},"items":[{"line_number":1,"line_type":1,"item_code":"SP001","item_name":"Điều chỉnh tăng mặt hàng Sản phẩm A","unit":"cái","quantity":1,"unit_price":500000,"tax_rate":10,"discount_tax":10,"discount_amount":100000,"before_discount_and_tax_amount":500000,"sub_amount":400000,"tax_amount":40000,"amount":440000}],"notes":"Điều chỉnh tăng đơn giá cho hóa đơn ký hiệu C26TSE số 589 ngày 26/01/2026","total_amount":4950000}'

Sample Parameters per Adjustment Type

Increase adjustment (increase)

{
    "provider_account_id": "{{your-provider-account-id}}",
    "original_invoice_reference_code": "084e179d-d95a-11f0-aef4-52c7e9b4f41b",
    "adjustment_type": "increase",
    "items": [
        {
            "line_number": 1,
            "line_type": 1,
            "item_code": "SP001",
            "item_name": "Điều chỉnh tăng mặt hàng Sản phẩm A",
            "unit": "cái",
            "quantity": 1,
            "unit_price": 500000,
            "tax_rate": 10
        }
    ],
    "notes": "Điều chỉnh tăng đơn giá cho hóa đơn ký hiệu C26TSE số 589 ngày 26/01/2026",
    "is_draft": false
}

Decrease adjustment (decrease - negative values)

{
    "provider_account_id": "{{your-provider-account-id}}",
    "original_invoice_reference_code": "084e179d-d95a-11f0-aef4-52c7e9b4f41b",
    "adjustment_type": "decrease",
    "items": [
        {
            "line_number": 1,
            "line_type": 1,
            "item_code": "SP001",
            "item_name": "Điều chỉnh giảm mặt hàng Sản phẩm A",
            "unit": "cái",
            "quantity": 1,
            "unit_price": -500000,
            "tax_rate": 10
        }
    ],
    "notes": "Điều chỉnh giảm đơn giá cho hóa đơn ký hiệu C26TSE số 589 ngày 26/01/2026",
    "is_draft": false
}

Combined adjustment (combined - per-line signs)

{
    "provider_account_id": "{{your-provider-account-id}}",
    "original_invoice_reference_code": "084e179d-d95a-11f0-aef4-52c7e9b4f41b",
    "adjustment_type": "combined",
    "items": [
        {
            "line_number": 1,
            "line_type": 1,
            "item_code": "SP001",
            "item_name": "Điều chỉnh tăng mặt hàng Sản phẩm A",
            "unit": "cái",
            "quantity": 1,
            "unit_price": 300000,
            "tax_rate": 10
        },
        {
            "line_number": 2,
            "line_type": 1,
            "item_code": "SP002",
            "item_name": "Điều chỉnh giảm mặt hàng Sản phẩm B",
            "unit": "cái",
            "quantity": 1,
            "unit_price": -200000,
            "tax_rate": 10
        }
    ],
    "notes": "Điều chỉnh tăng/giảm cho hóa đơn ký hiệu C26TSE số 589 ngày 26/01/2026",
    "is_draft": false
}

Information adjustment (info - zero totals, buyer required)

{
    "provider_account_id": "{{your-provider-account-id}}",
    "original_invoice_reference_code": "084e179d-d95a-11f0-aef4-52c7e9b4f41b",
    "adjustment_type": "info",
    "buyer": {
        "type": "company",
        "name": "Công ty ABC",
        "legal_name": "CÔNG TY TNHH ABC",
        "tax_code": "0101234567",
        "address": "456 Đường B, Quận C, Hà Nội",
        "email": "buyer@example.com"
    },
    "items": [
        {
            "line_number": 1,
            "line_type": 4,
            "item_name": "Điều chỉnh địa chỉ người mua từ 123 Đường A thành 456 Đường B"
        }
    ],
    "notes": "Điều chỉnh thông tin cho hóa đơn ký hiệu C26TSE số 589 ngày 26/01/2026",
    "is_draft": false
}

Adjusting only the line total after tax

{
    "provider_account_id": "{{your-provider-account-id}}",
    "original_invoice_reference_code": "084e179d-d95a-11f0-aef4-52c7e9b4f41b",
    "adjustment_type": "decrease",
    "items": [
        {
            "line_number": 1,
            "line_type": 1,
            "item_code": "SP001",
            "item_name": "Điều chỉnh giảm mặt hàng Sản phẩm A",
            "unit": "cái",
            "tax_rate": 10,
            "amount": -550000
        }
    ],
    "notes": "Điều chỉnh giảm thành tiền cho hóa đơn ký hiệu C26TSE số 589 ngày 26/01/2026",
    "is_draft": false
}

Next Steps

After a successful request returning a tracking_code:

1. Track invoice status - Use the tracking_code to check the processing result (required)