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Invoice API documentation

The Invoice Feed API allows merchants to upload invoice data in real-time or in bulk. Invoice data flows automatically and securely into Lovat, enabling businesses to generate, manage, and track invoices efficiently while maintaining compliance with tax regulations and accounting standards.

Terms and abbreviations

  • API – Application Programming Interface. A set of calls provided by the system for integration with external software products.
  • Merchant – The owner of an online store or business using the Lovat platform.
  • Customer – An individual or business entity who purchases goods or services from the merchant.
  • Invoice – A commercial document issued by a seller to a buyer, indicating the products, quantities, and agreed prices for products or services.
  • Token – A secret string used by the system to identify the merchant and authenticate API requests.
  • Line Item – Individual product or service entry in an invoice with quantity, unit price, and total.

 

Invoice data parameters

Parameter Type/Example Description Validation
invoice_number String/”INV-2024-001″ Unique invoice identifier Optional. Maximum 255 characters
customer_id Integer/123 Existing customer ID in system Optional. Must exist in customer database
customer_name String/”Acme Corporation” Customer business name Required. Maximum 255 characters. Not empty
customer_email String/”contact@acme.com” Customer email address Optional. Must contain ‘@’ if provided
customer_country String/”USA” Customer country code Optional. ISO 3166-1 alpha-3 format (3 characters)
customer_tax_number String/”123456789″ Customer tax/VAT number Optional. Maximum 25 characters
customer_address String/”123 Business St” Customer address Optional. Maximum 255 characters
invoice_date String/”2024-01-15″ Invoice creation date Required. YYYY-MM-DD format
due_date String/”2024-02-15″ Payment due date Optional. YYYY-MM-DD format
currency String/”EUR” Invoice currency Optional. Default: “EUR”. Maximum 3 characters
status String/”draft” Invoice status Required. Values: “draft”, “pending”, “sent”, “paid”
line_items Array List of invoice items Required. At least one item required
subtotal Float/1000.00 Sum before taxes and discounts Required. Decimal with 2 places
total_tax Float/220.00 Total tax amount Required. Decimal with 2 places
total Float/1220.00 Final invoice amount Required. Decimal with 2 places
total_discount_amount Float/50.00 Total discount amount Required. Decimal with 2 places
supplier_tax_number String/”987654321″ Supplier tax number Optional. Maximum 25 characters
supplier_country String/”USA” Supplier country code Optional. ISO 3166-1 alpha-3 format

Line item parameters

Parameter Type/Example Description Validation
description String/”Web Development” Item description Required. Maximum 255 characters
quantity Float/2.0 Item quantity Required. Positive number
unit_price Float/500.00 Price per unit Required. Positive number
is_taxable Boolean/true Whether item is taxable Default: true

API methods

1. Bulk invoice upload

  • Description: Upload one or multiple invoices to the platform in a single request.
  • Method: POST
  • URL: https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/{access_token}
  • Parameters:
    Path parameters: access_token (required)
    Body parameters: Array of invoice objects (JSON format)

 

Example requests

Bulk invoice upload


curl -X POST \\
"https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token" \\
  -H "Content-Type: application/json" \\
  -d '[
    {
      "invoice_number": "INV-2024-001",
      "customer_name": "Acme Corporation",
      "customer_email": "contact@acme.com",
      "customer_country": "USA",
      "customer_tax_number": "123456789",
      "customer_address": "123 Business Ave, New York, NY 10001",
      "invoice_date": "2024-01-15",
      "due_date": "2024-02-15",
      "currency": "USD",
      "status": "draft",
      "line_items": [
        {
          "description": "Web Development Services",
          "quantity": 40,
          "unit_price": 75.00,
          "tax": true
        },
        {
          "description": "Domain Registration",
          "quantity": 1,
          "unit_price": 15.00,
          "tax": false
        }
 ],
      "subtotal": 3015.00,
      "total_tax": 663.30,
      "total": 3678.30,
      "total_discount_amount": 0.00,
      "supplier_tax_number": "987654321",
      "supplier_country": "USA"
    },
    {
      "invoice_number": "INV-2024-002",
      "customer_name": "Tech Solutions Ltd",
      "customer_email": "info@techsolutions.com",
      "customer_country": "GBR",
      "customer_tax_number": "GB123456789",
      "customer_address": "456 Tech Street, London, SW1A 1AA",
      "invoice_date": "2024-01-16",
      "due_date": "2024-02-16",
      "currency": "EUR",
      "status": "draft",
      "line_items": [
        {
          "description": "Software License",
          "quantity": 1,
          "unit_price": 299.00,
          "tax": true
        }
      ],
      "subtotal": 299.00,
      "total_tax": 65.78,
      "total": 364.78,
      "total_discount_amount": 0.00,
      "supplier_tax_number": "987654321",
      "supplier_country": "USA"
    }
  ]'



import requests
import json

url = "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token"
headers = {"Content-Type": "application/json"}

invoices = [
    {
        "invoice_number": "INV-2024-001",
        "customer_name": "Acme Corporation",
        "customer_email": "contact@acme.com",
        "customer_country": "USA",
        "customer_tax_number": "123456789",
        "customer_address": "123 Business Ave, New York, NY 10001",
        "invoice_date": "2024-01-15",
        "due_date": "2024-02-15",
        "currency": "USD",
        "status": "draft",
        "line_items": [
            {
                "description": "Web Development Services",
                "quantity": 40,
                "unit_price": 75.00,
                "tax": True
            },
            {
                "description": "Domain Registration",
                "quantity": 1,
                "unit_price": 15.00,
                "tax": False
            }
        ],
        "subtotal": 3015.00,
        "total_tax": 663.30,
        "total": 3678.30,
        "total_discount_amount": 0.00,
        "supplier_tax_number": "987654321",
        "supplier_country": "USA"
    }
]

response = requests.post(url, headers=headers, data=json.dumps(invoices))
print(response.json())


require 'net/http'
require 'uri'
require 'json'

url = URI("https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

headers = { "Content-Type" => "application/json" }

invoices = [
  {
    "invoice_number" => "INV-2024-001",
    "customer_name" => "Acme Corporation",
    "customer_email" => "contact@acme.com",
    "customer_country" => "USA",
    "customer_tax_number" => "123456789",
    "customer_address" => "123 Business Ave, New York, NY 10001",
    "invoice_date" => "2024-01-15",
    "due_date" => "2024-02-15",
    "currency" => "USD",
    "status" => "draft",
    "line_items" => [
      {
        "description" => "Web Development Services",
        "quantity" => 40,
        "unit_price" => 75.00,
        "tax" => true
      },
      {
        "description" => "Domain Registration",
        "quantity" => 1,
        "unit_price" => 15.00,
        "tax" => false
      }
    ],
    "subtotal" => 3015.00,
    "total_tax" => 663.30,
    "total" => 3678.30,
    "total_discount_amount" => 0.00,
    "supplier_tax_number" => "987654321",
    "supplier_country" => "USA"
  }
]

request = Net::HTTP::Post.new(url, headers)
request.body = invoices.to_json

response = http.request(request)
puts response.body

<?php
$url = "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token";

$invoices = [
    [
        "invoice_number" => "INV-2024-001",
        "customer_name" => "Acme Corporation",
        "customer_email" => "contact@acme.com",
        "customer_country" => "USA",
        "customer_tax_number" => "123456789",
        "customer_address" => "123 Business Ave, New York, NY 10001",
        "invoice_date" => "2024-01-15",
        "due_date" => "2024-02-15",
        "currency" => "USD",
        "status" => "draft",
        "line_items" => [
            [
                "description" => "Web Development Services",
                "quantity" => 40,
                "unit_price" => 75.00,
                "tax" => true
            ],
            [
                "description" => "Domain Registration",
                "quantity" => 1,
                "unit_price" => 15.00,
                "tax" => false
            ]
        ],
        "subtotal" => 3015.00,
        "total_tax" => 663.30,
        "total" => 3678.30,
        "total_discount_amount" => 0.00,
        "supplier_tax_number" => "987654321",
        "supplier_country" => "USA"
    ]
];

$options = [
    "http" => [
        "header"  => "Content-Type: application/json\r\n",
        "method"  => "POST",
        "content" => json_encode($invoices),
    ]
];

$context  = stream_context_create($options);
$result = file_get_contents($url, false, $context);

if ($result === FALSE) {
    die("Error sending request");
}

echo $result;
?>

const fetch = require("node-fetch");

const url = "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token";
const invoices = [
  {
    invoice_number: "INV-2024-001",
    customer_name: "Acme Corporation",
    customer_email: "contact@acme.com",
    customer_country: "USA",
    customer_tax_number: "123456789",
    customer_address: "123 Business Ave, New York, NY 10001",
    invoice_date: "2024-01-15",
    due_date: "2024-02-15",
    currency: "USD",
    status: "draft",
    line_items: [
      {
        description: "Web Development Services",
        quantity: 40,
        unit_price: 75.00,
        tax: true
      },
      {
        description: "Domain Registration",
        quantity: 1,
        unit_price: 15.00,
        tax: false
      }
    ],
  subtotal: 3015.00,
    total_tax: 663.30,
    total: 3678.30,
    total_discount_amount: 0.00,
    supplier_tax_number: "987654321",
    supplier_country: "USA"
  }
];

fetch(url, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify(invoices),
})
  .then(res => res.json())
  .then(json => console.log(json))
  .catch(err => console.error("Error:", err));

using System;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

class Program {
    static async Task Main() {
        var url = "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token";
        var client = new HttpClient();

        var invoices = new[] {
            new {
                invoice_number = "INV-2024-001",
                customer_name = "Acme Corporation",
                customer_email = "contact@acme.com",
                customer_country = "USA",
                customer_tax_number = "123456789",
                customer_address = "123 Business Ave, New York, NY 10001",
                invoice_date = "2024-01-15",
                due_date = "2024-02-15",
                currency = "USD",
                status = "draft",
                line_items = new[] {
                    new {
                        description = "Web Development Services",
                        quantity = 40,
                        unit_price = 75.00,
                        tax = true
                    },
                    new {
                        description = "Domain Registration",
                        quantity = 1,
                        unit_price = 15.00,
                        tax = false
                    }
                },
                subtotal = 3015.00,
                total_tax = 663.30,
                total = 3678.30,
                total_discount_amount = 0.00,
                supplier_tax_number = "987654321",
                supplier_country = "USA"
            }
        };

        var json = Newtonsoft.Json.JsonConvert.SerializeObject(invoices);
        var content = new StringContent(json, Encoding.UTF8, "application/json");

        var response = await client.PostAsync(url, content);
        string responseBody = await response.Content.ReadAsStringAsync();

        Console.WriteLine(responseBody);
    }
}


import java.net.http.*;
import java.net.URI;
import java.nio.charset.StandardCharsets;

public class BulkInvoiceUpload {
    public static void main(String[] args) throws Exception {
        String url = "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token";

        String json = "[{\\"invoice_number\\":\\"INV-2024-001\\",\\"customer_name\\":\\"Acme Corporation\\",\\"customer_email\\":\\"contact@acme.com\\",\\"customer_country\\":\\"USA\\",\\"customer_tax_number\\":\\"123456789\\",\\"customer_address\\":\\"123 Business Ave, New York, NY 10001\\",\\"invoice_date\\":\\"2024-01-15\\",\\"due_date\\":\\"2024-02-15\\",\\"currency\\":\\"USD\\",\\"status\\":\\"draft\\",\\"line_items\\":[{\\"description\\":\\"Web Development Services\\",\\"quantity\\":40,\\"unit_price\\":75.00,\\"tax\\":true},{\\"description\\":\\"Domain Registration\\",\\"quantity\\":1,\\"unit_price\\":15.00,\\"tax\\":false}],\\"subtotal\\":3015.00,\\"total_tax\\":663.30,\\"total\\":3678.30,\\"total_discount_amount\\":0.00,\\"supplier_tax_number\\":\\"987654321\\",\\"supplier_country\\":\\"USA\\"}]";

        HttpClient client = HttpClient.newHttpClient();
        HttpRequest request = HttpRequest.newBuilder()
            .uri(URI.create(url))
            .header("Content-Type", "application/json")
            .POST(HttpRequest.BodyPublishers.ofString(json, StandardCharsets.UTF_8))
            .build();

        HttpResponse response = client.send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println(response.body());
    }
}


package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "net/http"
    "io/ioutil"
)

func main() {
    url := "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token"

    invoices := []map[string]interface{}{
        {
            "invoice_number":        "INV-2024-001",
            "customer_name":         "Acme Corporation",
            "customer_email":        "contact@acme.com",
            "customer_country":      "USA",
            "customer_tax_number":   "123456789",
            "customer_address":      "123 Business Ave, New York, NY 10001",
            "invoice_date":          "2024-01-15",
            "due_date":              "2024-02-15",
            "currency":              "USD",
            "status":                "draft",
            "line_items": []map[string]interface{}{
                {
                    "description": "Web Development Services",
                    "quantity":     40,
                    "unit_price":   75.00,
                    "tax":          true,
                },
                {
                    "description": "Domain Registration",
                    "quantity":     1,
                    "unit_price":   15.00,
                    "tax":          false,
                },
            },
            "subtotal":             3015.00,
            "total_tax":            663.30,
            "total":                3678.30,
            "total_discount_amount": 0.00,
            "supplier_tax_number":   "987654321",
            "supplier_country":      "USA",
        },
    }

    body, _ := json.Marshal(invoices)
    resp, err := http.Post(url, "application/json", bytes.NewBuffer(body))
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    responseData, _ := ioutil.ReadAll(resp.Body)
    fmt.Println(string(responseData))
}

Example response

Invoice upload response

{
  "status": "done",
  "results": [
    {
      "index": 0,
      "status": "success",
      "invoice_id": 5290,
      "invoice_number": "INV-2024-009",
      "total": "3678.3"
    }
  ]
}

2. Invoice update

  • Description: Update an existing invoice by its unique identifier. Supports partial updates – only provided fields will be modified.
  • Method: PUT
  • URL: https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/{access_token}/{invoice_id}
  • Parameters:
    – Path parameters:
    access_token (required) – Authentication token
    invoice_id (required) – Unique invoice identifier
    – Body parameters: Invoice update object (JSON format)

 

Example requests

Update invoice by ID

curl -X PUT \\
"https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token/1234" \\
  -H "Content-Type: application/json" \\
  -d '{
    "invoice_date": "2024-01-20",
    "due_date": "2024-02-20",
    "status": "sent",
    "line_items": [
      {
        "description": "Updated Web Development Services",
        "quantity": 45,
        "unit_price": 80.00,
        "tax": true
      },
      {
        "description": "Additional Consulting",
        "quantity": 5,
        "unit_price": 100.00,
        "tax": true
      }
    ],
    "subtotal": 4100.00,
    "total_tax": 902.00,
    "total": 5002.00,
    "total_discount_amount": 0.00
  }'


import requests
import json

url = "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token/1234"
headers = {"Content-Type": "application/json"}

update_data = {
    "invoice_date": "2024-01-20",
    "due_date": "2024-02-20",
    "status": "sent",
    "line_items": [
        {
            "description": "Updated Web Development Services",
            "quantity": 45,
            "unit_price": 80.00,
            "tax": True
        },
        {
            "description": "Additional Consulting",
            "quantity": 5,
            "unit_price": 100.00,
            "tax": True
        }
    ],
    "subtotal": 4100.00,
    "total_tax": 902.00,
    "total": 5002.00,
    "total_discount_amount": 0.00
}

response = requests.put(url, headers=headers, data=json.dumps(update_data))
print(response.json())



require 'net/http'
require 'uri'
require 'json'

url = URI("https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token/1234")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

headers = { "Content-Type" => "application/json" }

update_data = {
  "invoice_date" => "2024-01-20",
  "due_date" => "2024-02-20",
  "status" => "sent",
  "line_items" => [
    {
      "description" => "Updated Web Development Services",
      "quantity" => 45,
      "unit_price" => 80.00,
      "tax" => true
    },
    {
      "description" => "Additional Consulting",
      "quantity" => 5,
      "unit_price" => 100.00,
      "tax" => true
    }
  ],
  "subtotal" => 4100.00,
  "total_tax" => 902.00,
  "total" => 5002.00,
  "total_discount_amount" => 0.00
}

request = Net::HTTP::Put.new(url, headers)
request.body = update_data.to_json

response = http.request(request)
puts response.body


<?php
$url = "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token/1234";

$update_data = [
    "invoice_date" => "2024-01-20",
    "due_date" => "2024-02-20",
    "status" => "sent",
    "line_items" => [
        [
            "description" => "Updated Web Development Services",
            "quantity" => 45,
            "unit_price" => 80.00,
            "tax" => true
        ],
        [
            "description" => "Additional Consulting",
            "quantity" => 5,
            "unit_price" => 100.00,
            "tax" => true
        ]
    ],
    "subtotal" => 4100.00,
    "total_tax" => 902.00,
    "total" => 5002.00,
    "total_discount_amount" => 0.00
];

$options = [
    "http" => [
        "header"  => "Content-Type: application/json\r\n",
        "method"  => "PUT",
        "content" => json_encode($update_data),
    ]
];

$context  = stream_context_create($options);
$result = file_get_contents($url, false, $context);

if ($result === FALSE) {
    die("Error sending request");
}

echo $result;
?>
const fetch = require("node-fetch");

const url = "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token/1234";
const update_data = {
  invoice_date: "2024-01-20",
  due_date: "2024-02-20",
  status: "sent",
  line_items: [
    {
      description: "Updated Web Development Services",
      quantity: 45,
      unit_price: 80.00,
      tax: true
    },
    {
      description: "Additional Consulting",
      quantity: 5,
      unit_price: 100.00,
      tax: true
    }
  ],
  subtotal: 4100.00,
  total_tax: 902.00,
  total: 5002.00,
  total_discount_amount: 0.00
};

fetch(url, {
  method: "PUT",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify(update_data),
})
  .then(res => res.json())
  .then(json => console.log(json))
  .catch(err => console.error("Error:", err));

.Net

using System;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

class Program {
    static async Task Main() {
        var url = "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token/1234";
        var client = new HttpClient();

        var update_data = new {
            invoice_date = "2024-01-20",
            due_date = "2024-02-20",
            status = "sent",
            line_items = new[] {
                new {
                    description = "Updated Web Development Services",
                    quantity = 45,
                    unit_price = 80.00,
                    tax = true
                },
                new {
                    description = "Additional Consulting",
                    quantity = 5,
                    unit_price = 100.00,
                    tax = true
                }
            },
            subtotal = 4100.00,
            total_tax = 902.00,
            total = 5002.00,
            total_discount_amount = 0.00
        };

        var json = Newtonsoft.Json.JsonConvert.SerializeObject(update_data);
        var content = new StringContent(json, Encoding.UTF8, "application/json");

        var response = await client.PutAsync(url, content);
        string responseBody = await response.Content.ReadAsStringAsync();

        Console.WriteLine(responseBody);
    }
}

import java.net.http.*;
import java.net.URI;
import java.nio.charset.StandardCharsets;

public class UpdateInvoice {
    public static void main(String[] args) throws Exception {
        String url = "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token/1234";

        String json = "{\\"invoice_date\\":\\"2024-01-20\\",\\"due_date\\":\\"2024-02-20\\",\\"status\\":\\"sent\\",\\"line_items\\":[{\\"description\\":\\"Updated Web Development Services\\",\\"quantity\\":45,\\"unit_price\\":80.00,\\"tax\\":true},{\\"description\\":\\"Additional Consulting\\",\\"quantity\\":5,\\"unit_price\\":100.00,\\"tax\\":true}],\\"subtotal\\":4100.00,\\"total_tax\\":902.00,\\"total\\":5002.00,\\"total_discount_amount\\":0.00}";

        HttpClient client = HttpClient.newHttpClient();
        HttpRequest request = HttpRequest.newBuilder()
            .uri(URI.create(url))
            .header("Content-Type", "application/json")
            .PUT(HttpRequest.BodyPublishers.ofString(json, StandardCharsets.UTF_8))
            .build();

        HttpResponse response = client.send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println(response.body());
    }
}


package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "net/http"
    "io/ioutil"
)

func main() {
    url := "https://invoice.vatcompliance.co/api/1/app/l_invoice/invoices/your-access-token/1234"

    update_data := map[string]interface{}{
        "invoice_date": "2024-01-20",
        "due_date":     "2024-02-20",
        "status":       "sent",
        "line_items": []map[string]interface{}{
            {
                "description": "Updated Web Development Services",
                "quantity":     45,
                "unit_price":   80.00,
                "tax":          true,
            },
 {
                "description": "Additional Consulting",
                "quantity":     5,
                "unit_price":   100.00,
                "tax":          true,
            },
        },
        "subtotal":              4100.00,
        "total_tax":             902.00,
        "total":                 5002.00,
        "total_discount_amount": 0.00,
    }

    body, _ := json.Marshal(update_data)
    req, _ := http.NewRequest("PUT", url, bytes.NewBuffer(body))
    req.Header.Set("Content-Type", "application/json")

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    responseData, _ := ioutil.ReadAll(resp.Body)
    fmt.Println(string(responseData))
}

Example responses

Update invoice response

Success response


{
  "status": 200,
  "message": "Invoice 'INV-2024-001' (ID: 5289) updated successfully",
  "invoice": {
    "id": 5289,
    "invoice_number": "INV-2024-001",
    "customer_name": "Acme Corporation",
    "total": "5002.0",
    "currency": "USD",
    "created_date": "2024-01-20",
    "due_date": "2024-02-20"
  }
}

Limitations and best practices

  • Rate Limiting: Maximum 100 requests per minute per access token
  • Partial Updates: Only provided fields will be updated, others remain unchanged
  • Data Validation: All update data is validated before processing
  • Line Items: If updating line items, must provide complete new list
  • Date Format: All dates must be in YYYY-MM-DD format
  • Decimal Precision: All monetary values support 2 decimal places