# Tax rules

Create a tax rule to be associated with a [manual tax calculator](/core-api-reference/manual_tax_calculators.md). Use the available regular expressions to match the order shipping address and apply the specified `tax_rate` (default is `0`). You can optionally define the tax rule taxable preferences by setting the `freight_taxable`, `payment_method_taxable`, `gift_card_taxable`, and `adjustment_taxable` attributes to `true` (all `false` by default).

{% hint style="info" %}
Manual tax calculators support **location-based** tax rules only, meaning that they can evaluate RegEx (max **5000** chars allowed) to match the shipping address country, state, and zip codes. For any other use case please consider creating an [external tax calculator](/core-api-reference/external_tax_calculators.md) that handles your own custom tax calculation logic or leveraging our out-of-the-box integrations with [Avalara](/core-api-reference/avalara_accounts.md), [Stripe Tax](/core-api-reference/stripe_tax_accounts.md), [TaxJar](/core-api-reference/taxjar_accounts.md), and [Vertex](/core-api-reference/vertex_accounts.md).
{% endhint %}

<details>

<summary>Data model</summary>

Check the related [ER diagram](/data-model/payments-and-tax/tax-calculation.md) and explore the flowchart that illustrates how the tax rule resource relates to the other API entities.

</details>


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