# Calculate an invoice

`POST https://api.leapa.co/v2/invoices/calculate`

Send your API key as a bearer token in the `Authorization` header.

## Request body

Required. `application/json`.

- `description` · _string_ · **required** —  Description of the invoice. Constraints: Not null, min=3 and max=120
  Must be: 3 to 120 characters
- `affiliate` · _string_ — affiliate that can be used on this invoice
  Allowed values: `dwelinn`
- `sendForManualPayment` · _boolean_
- `customer_id` · _string_ · **required** —  Customer Id. Constraints: Not null  
- `products` · _array of ItemRequest_ · **required** —  List of product and quantity. Constraints: Not null, Not Empty
  - `quantity` · _integer<int64>_ · **required** —  Quantity for this product. Constraints: Not null
  - `product_id` · _string_ · **required** —  Product Identifications. Constraints: Not Null 
  - `rate_ids` · _array of string_ — RateIds 
- `due_date` · _string<date>_ · **required** —  Invoice due date. Constraints: Not null, format(YYYY-MM-DD)
- `source_id` · _string_ — Customer existing source information.
- `manual_payment` · _boolean_ —  Collection Method of this invoice: If the payment is automatic then the system will charge against the customer register card. If it is manual the system will send an email to the customer with payment instruction.
- `rate_id` · _string_ — Rate Id that can be used on this invoice.
- `amount_to_paid` · _number<double>_ —  this is for partial payment of an invoice
- `custom_fields` · _object_ — Extra key/value pairs carried with the invoice. Every value has to be a string. For Burundi tax collection, set obr_code to the OBR payment code the payment belongs to, for example ADB_REGISTRE_COMMERCE. Leapa sends that code to OBR when the invoice is paid and puts the quittance number OBR issues on the invoice, as quittance_number. Write once: the invoice does not return custom_fields, and updating an invoice cannot change it, so keep your own record of which code you sent.
  Example: `{"obr_code":"ADB_REGISTRE_COMMERCE"}`

```json
{
  "description": "Room 204, two nights",
  "affiliate": "dwelinn",
  "sendForManualPayment": false,
  "customer_id": "cus_3d8e51fa20",
  "products": [
    {
      "quantity": 1,
      "product_id": "prd_84c2e7f019",
      "rate_ids": []
    }
  ],
  "due_date": "2026-01-31",
  "source_id": "src_0e7b3c95af",
  "manual_payment": false,
  "rate_id": "rat_20b6df3c9e",
  "amount_to_paid": 45000,
  "custom_fields": {
    "obr_code": "ADB_REGISTRE_COMMERCE"
  }
}
```

## Response 200

- `currency` · _string_ —  Currency of the amount in the invoice. 
  Allowed values: `BIF`, `USD`, `KES`, `XAF`
- `amount_due` · _integer<int64>_ — amount upon applying the rate to be paid for this Invoice. 
- `rate_id` · _string_ — Rate Id that can be used on this invoice.

```json
{
  "currency": "BIF",
  "amount_due": 45000,
  "rate_id": "rat_20b6df3c9e"
}
```

## Status codes

- `200` OK
- `400` Bad request
- `401` Unauthorized
- `402` Payment required
- `403` Forbidden
- `404` Not found
- `428` Precondition required
- `500` Server error

## Example

```bash
curl -X POST "https://api.leapa.co/v2/invoices/calculate" \
  -H "Authorization: Bearer $LEAPA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "description": "Room 204, two nights",
    "affiliate": "dwelinn",
    "sendForManualPayment": false,
    "customer_id": "cus_3d8e51fa20",
    "products": [
      {
        "quantity": 1,
        "product_id": "prd_84c2e7f019",
        "rate_ids": []
      }
    ],
    "due_date": "2026-01-31",
    "source_id": "src_0e7b3c95af",
    "manual_payment": false,
    "rate_id": "rat_20b6df3c9e",
    "amount_to_paid": 45000,
    "custom_fields": {
      "obr_code": "ADB_REGISTRE_COMMERCE"
    }
  }'
```

---

_Generated from the Leapa documentation at leapa.co/docs._