# `TaxRate`

A rate of tax, as a percentage that can't be below zero: `20%`.

Use it for VAT or sales tax. For any other percentage, use [`Percentage`](/docs/types/type-percentage.md). For a discount, use [`Discount`](/docs/types/type-discount.md).

## Shape

One `Percentage`, never below 0.

## Example

```jadpo
TaxRate(20%)
```

A value outside its limits breaks `min` or `max`.

`text.parse(raw, as: TaxRate)` reads one from text that comes from outside. Text that isn't one at all fails `malformed`, such as `20`, `0.2` or `twenty percent`.

## Good to know

- `==` tells you whether two are the same, and `<` and `list.sort_by` compare and sort them.

## In JSON

A string, in a request, a response or `json.write`:

```json
"0%"
"5%"
"20%"
```

## Details

<details>
<summary>Text form, storage, how it is shown, and operations</summary>

`TaxRate` is in the group Money and banking, and has been in Jadpo since 0.1.0.

### Text form

`text.from` writes one standard text form, the same form `text.parse` reads back: `0%`, `5%` and `20%`.

### How it is stored

It is stored in one column named for the field, of type `numeric`. `5%` is stored as `0.05`.

### How it is shown to people

`text.format(value, locale:)` shows it to people in their locale.

With `locale: Locale.en_gb`:

| Value | Shown |
|---|---|
| `0%` | `0%` |
| `5%` | `5%` |
| `20%` | `20%` |

### Operations

It also takes `text.parse`, `text.from`, `text.format`, `json.read`, `json.write` and `==`. [How every standard type behaves](/docs/every-standard-type-meets-one-contract.md) says how they work.

</details>