Umsatzsteuer

Accounting7 EndpointsBilling / Umsatzsteuer

Die Voranmeldung eines Zeitraums.

GET/api/invoice/vat_return

Query parameters

`year`string	Jahr, Vorgabe das laufende
`period`string	Monat 1-12 oder Quartal 1-4
`filing_period`string	MONTHLY oder QUARTERLY, überschreibt die Einstellung

Responses

200Die Voranmeldung mit den amtlichen Kennzahlen

Request

curl --request GET \
  --url https://your-instance.iw-erp.de/api/invoice/vat_return \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'GET', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/vat_return', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/vat_return"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.get(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://your-instance.iw-erp.de/api/invoice/vat_return', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Get,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/vat_return"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/vat_return")
  .get()
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/vat_return"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/vat_return_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await VatReturnController.get();
if (result.success) {
  print(result.data);
}

Alle Zeiträume eines Jahres mit ihrer Zahllast.

GET/api/invoice/vat_return/overview

Query parameters

`year`string	Jahr, Vorgabe das laufende
`filing_period`string	MONTHLY oder QUARTERLY

Responses

200Jahresüberblick der Voranmeldungen

Request

curl --request GET \
  --url https://your-instance.iw-erp.de/api/invoice/vat_return/overview \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'GET', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/vat_return/overview', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/vat_return/overview"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.get(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://your-instance.iw-erp.de/api/invoice/vat_return/overview', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Get,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/vat_return/overview"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/vat_return/overview")
  .get()
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/vat_return/overview"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/vat_return_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await VatReturnController.getOverview();
if (result.success) {
  print(result.data);
}

Welcher Voranmeldungszeitraum nach § 18 Abs. 2 UStG gilt.

GET/api/invoice/vat_return/filing_period

Ein Vorschlag mit Begründung: die Befreiung unterhalb der unteren Grenze ist eine Kann-Vorschrift des Finanzamts, keine Automatik.

Query parameters

yearstring Jahr, Vorgabe das laufende

Responses

200Vorschlag für den Voranmeldungszeitraum

Request

curl --request GET \
  --url https://your-instance.iw-erp.de/api/invoice/vat_return/filing_period \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'GET', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/vat_return/filing_period', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/vat_return/filing_period"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.get(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://your-instance.iw-erp.de/api/invoice/vat_return/filing_period', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Get,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/vat_return/filing_period"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/vat_return/filing_period")
  .get()
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/vat_return/filing_period"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/vat_return_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await VatReturnController.getFilingPeriodSuggestion();
if (result.success) {
  print(result.data);
}

Schreibt eine Voranmeldung als abgegeben fest.

POST/api/invoice/vat_return/submit

Ab hier stehen ihre Zahlen fest. Wird ein Beleg spaeter storniert oder archiviert, aendert das die abgegebene Anmeldung nicht mehr rueckwirkend - die Abweichung wird stattdessen ausgewiesen, und die Berichtigung ist eine neue Fassung desselben Zeitraums.

Request body application/json

yearinteger
periodinteger
filing_periodstring
correction_reasonstring
Pflicht ab der zweiten Fassung

Responses

200Die festgeschriebene Voranmeldung

Request

curl --request POST \
  --url https://your-instance.iw-erp.de/api/invoice/vat_return/submit \
  --header 'content-type: application/json' \
  --header 'x-iw-jwt-token: <TOKEN>' \
  --data '
{
  "year": 2026,
  "period": 1,
  "filing_period": "QUARTERLY",
  "correction_reason": "string"
}
'

const options = {
  method: 'POST',
  headers: {'x-iw-jwt-token': '<TOKEN>', 'content-type': 'application/json'},
  body: JSON.stringify({year: 2026, period: 1, filing_period: 'QUARTERLY', correction_reason: 'string'})
};

fetch('https://your-instance.iw-erp.de/api/invoice/vat_return/submit', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/vat_return/submit"

payload = {
  "year": 2026,
  "period": 1,
  "filing_period": "QUARTERLY",
  "correction_reason": "string"
}
headers = {
  "x-iw-jwt-token": "<TOKEN>",
  "content-type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://your-instance.iw-erp.de/api/invoice/vat_return/submit', [
  'body' => '{"year":2026,"period":1,"filing_period":"QUARTERLY","correction_reason":"string"}',
  'headers' => [
    'content-type' => 'application/json',
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Post,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/vat_return/submit"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
  Content = new StringContent("{\"year\":2026,\"period\":1,\"filing_period\":\"QUARTERLY\",\"correction_reason\":\"string\"}")
  {
    Headers =
    {
      ContentType = new MediaTypeHeaderValue("application/json")
    }
  }
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

MediaType mediaType = MediaType.parse("application/json");
RequestBody body = RequestBody.create(mediaType, "{\"year\":2026,\"period\":1,\"filing_period\":\"QUARTERLY\",\"correction_reason\":\"string\"}");
Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/vat_return/submit")
  .post(body)
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .addHeader("content-type", "application/json")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/vat_return/submit"

	payload := strings.NewReader("{\"year\":2026,\"period\":1,\"filing_period\":\"QUARTERLY\",\"correction_reason\":\"string\"}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")
	req.Header.Add("content-type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/vat_return_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await VatReturnController.submit(year: 42, period: 42);
if (result.success) {
  print(result.data);
}

Die umsatzsteuerlichen Sachverhalte und die Kennzahlen des Vordrucks.

GET/api/invoice/vat_return/categories

Der Steuersatz sagt nicht, in welche Zeile der Voranmeldung ein Umsatz gehoert: null Prozent stehen an einer innergemeinschaftlichen Lieferung, an einer Ausfuhr, an einer Leistung nach § 13b UStG und an einem steuerfreien Umsatz - vier verschiedene Zeilen. Der Sachverhalt haengt deshalb am Beleg, und diese Liste sagt, welche es gibt.

Responses

200Sachverhalte und Kennzahlen

Request

curl --request GET \
  --url https://your-instance.iw-erp.de/api/invoice/vat_return/categories \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'GET', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/vat_return/categories', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/vat_return/categories"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.get(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://your-instance.iw-erp.de/api/invoice/vat_return/categories', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Get,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/vat_return/categories"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/vat_return/categories")
  .get()
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/vat_return/categories"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/vat_return_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await VatReturnController.getCategories();
if (result.success) {
  print(result.data);
}

Alle Fassungen eines Zeitraums - der Verlauf einer Berichtigung.

GET/api/invoice/vat_return/filings

Query parameters

`year`string
`period`string
`filing_period`string	MONTHLY oder QUARTERLY

Responses

200Die abgegebenen Fassungen, aelteste zuerst

Request

curl --request GET \
  --url https://your-instance.iw-erp.de/api/invoice/vat_return/filings \
  --header 'x-iw-jwt-token: <TOKEN>'

const options = {method: 'GET', headers: {'x-iw-jwt-token': '<TOKEN>'}};

fetch('https://your-instance.iw-erp.de/api/invoice/vat_return/filings', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/vat_return/filings"

headers = {"x-iw-jwt-token": "<TOKEN>"}

response = requests.get(url, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://your-instance.iw-erp.de/api/invoice/vat_return/filings', [
  'headers' => [
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Get,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/vat_return/filings"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/vat_return/filings")
  .get()
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/vat_return/filings"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/vat_return_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await VatReturnController.getFilings();
if (result.success) {
  print(result.data);
}

Hält Zahlung oder Erstattung einer abgegebenen Voranmeldung fest.

POST/api/invoice/vat_return/filings/{id}/payment

Für die EÜR nach der Bruttomethode (billing_euer_gross_method): die gezahlte Umsatzsteuer ist Betriebsausgabe, die Erstattung Betriebseinnahme, jeweils am Tag der Zahlung. Ohne payment_date wird die Zahlung wieder entfernt.

Path parameters

idrequiredstring

Request body application/json

payment_datestring (date)
amountnumber
Positiv gezahlt, negativ erstattet; ohne Angabe die Kennzahl 83

Responses

200Die Voranmeldung mit Zahlung

Request

curl --request POST \
  --url https://your-instance.iw-erp.de/api/invoice/vat_return/filings/42/payment \
  --header 'content-type: application/json' \
  --header 'x-iw-jwt-token: <TOKEN>' \
  --data '
{
  "payment_date": "2026-01-08",
  "amount": 49.9
}
'

const options = {
  method: 'POST',
  headers: {'x-iw-jwt-token': '<TOKEN>', 'content-type': 'application/json'},
  body: JSON.stringify({payment_date: '2026-01-08', amount: 49.9})
};

fetch('https://your-instance.iw-erp.de/api/invoice/vat_return/filings/42/payment', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://your-instance.iw-erp.de/api/invoice/vat_return/filings/42/payment"

payload = {
  "payment_date": "2026-01-08",
  "amount": 49.9
}
headers = {
  "x-iw-jwt-token": "<TOKEN>",
  "content-type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://your-instance.iw-erp.de/api/invoice/vat_return/filings/42/payment', [
  'body' => '{"payment_date":"2026-01-08","amount":49.9}',
  'headers' => [
    'content-type' => 'application/json',
    'x-iw-jwt-token' => '<TOKEN>',
  ],
]);

echo $response->getBody();

using System.Net.Http.Headers;
var client = new HttpClient();
var request = new HttpRequestMessage
{
  Method = HttpMethod.Post,
  RequestUri = new Uri("https://your-instance.iw-erp.de/api/invoice/vat_return/filings/42/payment"),
  Headers =
  {
    { "x-iw-jwt-token", "<TOKEN>" },
  },
  Content = new StringContent("{\"payment_date\":\"2026-01-08\",\"amount\":49.9}")
  {
    Headers =
    {
      ContentType = new MediaTypeHeaderValue("application/json")
    }
  }
};
using (var response = await client.SendAsync(request))
{
  response.EnsureSuccessStatusCode();
  var body = await response.Content.ReadAsStringAsync();
  Console.WriteLine(body);
}

OkHttpClient client = new OkHttpClient();

MediaType mediaType = MediaType.parse("application/json");
RequestBody body = RequestBody.create(mediaType, "{\"payment_date\":\"2026-01-08\",\"amount\":49.9}");
Request request = new Request.Builder()
  .url("https://your-instance.iw-erp.de/api/invoice/vat_return/filings/42/payment")
  .post(body)
  .addHeader("x-iw-jwt-token", "<TOKEN>")
  .addHeader("content-type", "application/json")
  .build();

Response response = client.newCall(request).execute();

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://your-instance.iw-erp.de/api/invoice/vat_return/filings/42/payment"

	payload := strings.NewReader("{\"payment_date\":\"2026-01-08\",\"amount\":49.9}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("x-iw-jwt-token", "<TOKEN>")
	req.Header.Add("content-type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

Dart with the iw_erp_api package

import 'package:iw_erp_api/clients/vat_return_controller.dart';
import 'package:iw_erp_api/logic/iw_api_state.dart';

IwApiState().host = 'your-instance.iw-erp.de';
IwApiState().currentJwtApiToken = '<TOKEN>';

final result = await VatReturnController.recordPayment(filingId: 42, paymentDate: DateTime.fromJson({
  "payment_date": "2026-01-08",
  "amount": 49.9
}));
if (result.success) {
  print(result.data);
}