---
title: "UstgRules – API-Referenz · Quittio"
description: "Mandatory invoice information according to the German VAT act: section 14 (4) and 14a UStG, section 33 UStDV for small amount invoices and section 34a UStDV for small business invoices."
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> Index of every page on this site: [llms.txt](https://quittio.dev/llms.txt)

[API reference](https://quittio.dev/docs/api) / [Quittio](https://quittio.dev/docs/api/Quittio) \\ [Country](https://quittio.dev/docs/api/Quittio/Country) \\ [DE](https://quittio.dev/docs/api/Quittio/Country/DE) \\ [Rules](https://quittio.dev/docs/api/Quittio/Country/DE/Rules)

# UstgRules

final class in quittio/country-de

`Quittio\Country\DE\Rules\UstgRules` · [Source](https://github.com/Quittio/quittio/blob/v0.7.1/packages/country-de/src/Rules/UstgRules.php#L36)

Mandatory invoice information according to the German VAT act: section 14 (4) and 14a UStG, section 33 UStDV for small amount invoices and section 34a UStDV for small business invoices.

These rules apply to every invoice of a German seller, independent of the format.

## Methods \#

| Method | Description |
| --- | --- |
| `::all()` | |
| `::hasServiceDate()` | Whether the invoice states the date of the supply (section 14 (4) no. 6 UStG): a delivery date, an invoicing period or a period on every line. |
| `::isSmallAmountInvoice()` | Small amount invoice according to section 33 UStDV whose simplifications apply: not for supplies under sections 6a and 13b UStG (section 33 sentence 3 UStDV). Possible distance sales (section 3c UStG) keep the simplifications and get a DE-USTG-12 warning. |
| `::isSmallBusinessInvoice()` | Invoice of a small business (section 19 UStG, invoice according to section 34a UStDV): the small business flag is set or a line uses VatPreset::SmallBusiness. |
| `::issuingDeadline()` | The 15th day of the month after the supply (section 14a (1) sentence 2 and (3) sentence 1 UStG), see supplyDate(); null without a supply date (see DE-USTG-03). |
| `::plausibility()` | Plausibility of the Leitweg-ID (level L7). For public buyers (XRechnung or a Leitweg-ID endpoint, BT-49 scheme 0204) wrong check digits are a warning. Other business buyers in Germany get an info for a buyer reference shaped like a Leitweg-ID with wrong check digits: it may be a mistyped Leitweg-ID, which does not lead to XRechnung, or an ordinary order number. |
| `::supplyDate()` | The date of the supply that the invoice states: the latest of the delivery date, the end of the invoicing period and the ends of the line periods; null without any of them. |

### `all()`#

```
public static function all(): list<Rule>
```

static

<dl><dt>Returns</dt>
<dd><code>list&lt;<a href="https://quittio.dev/docs/api/Quittio/Core/Validation/Rule">Rule</a>&gt;</code></dd>
</dl>

### `hasServiceDate()`#

```
public static function hasServiceDate(InvoiceData $invoice): bool
```

static

Whether the invoice states the date of the supply (section 14 (4) no. 6 UStG): a delivery date, an invoicing period or a period on every line.

| Parameter | Type | Description |
| --- | --- | --- |
| `$invoice` | `[InvoiceData](https://quittio.dev/docs/api/Quittio/Core/Data/InvoiceData)` | |

<dl><dt>Returns</dt>
<dd><code>bool</code></dd>
</dl>

### `isSmallAmountInvoice()`#

```
public static function isSmallAmountInvoice(InvoiceData $invoice): bool
```

static

Small amount invoice according to section 33 UStDV whose simplifications apply: not for supplies under sections 6a and 13b UStG (section 33 sentence 3 UStDV). Possible distance sales (section 3c UStG) keep the simplifications and get a DE-USTG-12 warning.

| Parameter | Type | Description |
| --- | --- | --- |
| `$invoice` | `[InvoiceData](https://quittio.dev/docs/api/Quittio/Core/Data/InvoiceData)` | |

<dl><dt>Returns</dt>
<dd><code>bool</code></dd>
</dl>

### `isSmallBusinessInvoice()`#

```
public static function isSmallBusinessInvoice(InvoiceData $invoice): bool
```

static

Invoice of a small business (section 19 UStG, invoice according to section 34a UStDV): the small business flag is set or a line uses VatPreset::SmallBusiness.

| Parameter | Type | Description |
| --- | --- | --- |
| `$invoice` | `[InvoiceData](https://quittio.dev/docs/api/Quittio/Core/Data/InvoiceData)` | |

<dl><dt>Returns</dt>
<dd><code>bool</code></dd>
</dl>

### `issuingDeadline()`#

```
public static function issuingDeadline(InvoiceData $invoice): ?Date
```

static

The 15th day of the month after the supply (section 14a (1) sentence 2 and (3) sentence 1 UStG), see supplyDate(); null without a supply date (see DE-USTG-03).

| Parameter | Type | Description |
| --- | --- | --- |
| `$invoice` | `[InvoiceData](https://quittio.dev/docs/api/Quittio/Core/Data/InvoiceData)` | |

<dl><dt>Returns</dt>
<dd><code>?<a href="https://quittio.dev/docs/api/Quittio/Core/Support/Date">Date</a></code></dd>
</dl>

### `plausibility()`#

```
public static function plausibility(): list<Rule>
```

static

Plausibility of the Leitweg-ID (level L7). For public buyers (XRechnung or a Leitweg-ID endpoint, BT-49 scheme 0204) wrong check digits are a warning. Other business buyers in Germany get an info for a buyer reference shaped like a Leitweg-ID with wrong check digits: it may be a mistyped Leitweg-ID, which does not lead to XRechnung, or an ordinary order number.

<dl><dt>Returns</dt>
<dd><code>list&lt;<a href="https://quittio.dev/docs/api/Quittio/Core/Validation/Rule">Rule</a>&gt;</code></dd>
</dl>

### `supplyDate()`#

```
public static function supplyDate(InvoiceData $invoice): ?Date
```

static

The date of the supply that the invoice states: the latest of the delivery date, the end of the invoicing period and the ends of the line periods; null without any of them.

| Parameter | Type | Description |
| --- | --- | --- |
| `$invoice` | `[InvoiceData](https://quittio.dev/docs/api/Quittio/Core/Data/InvoiceData)` | |

<dl><dt>Returns</dt>
<dd><code>?<a href="https://quittio.dev/docs/api/Quittio/Core/Support/Date">Date</a></code></dd>
</dl>

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