> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gobl.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Filter

Filter selects rate totals from a document's tax totals by category and, optionally, key and extensions.

## Schema ID

`https://gobl.org/draft-0/tax/filter`

## Properties

| Title | Property | Type | Description |
| - | - | - | - |
| Category | `cat` | [cbc.Code](/draft-0/cbc/code) | Tax category code the rates must belong to. |
| Key | `key` | [cbc.Key](/draft-0/cbc/key) | Tax key the rates must have, if set. |
| Extensions | `ext` | [tax.Extensions](/draft-0/tax/extensions) | Extensions the rates must include, if set. |

## Validation Rules

| Field | Test | Validation Code / Message |
| - | - | - |
| `cat` | <ul class="gobl-test"><li class="gobl-test-present">Present</li></ul> | `GOBL-TAX-FILTER-01`<br />Tax filter category is required |


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