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 or an already-adjusted invoice. A replacement invoice cannot be adjusted.
• Not have been replaced or cancelled.

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

The first correction picks the form for every later one. An invoice that has been adjusted can only be adjusted again, never replaced. The other way round, a replacement invoice can only be replaced again, never adjusted.

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 decrease: line values may be sent as negative or positive numbers - the system keeps exactly what you send, the decrease nature is already carried by adjustment_type=decrease.
• 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 - adjust a discount through discount_amount directly, using the same sign convention as the item lines.
• When the origin is a sales invoice (template_code = 2): it carries no tax - any tax_rate/tax_amount you send is ignored and the tax is always 0.
• tax_amount on each line: when provided, it must be an integer (a value with decimals is rejected with a 400 error) and the system uses exactly the value you send without recomputing it from tax_rate.
• 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

The JSON below are illustrative request examples only - the figures and content are fictitious.

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)

The example below uses negative values - for decrease you may also send positive values, the system keeps what you send.

{
    "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)