Adding information about updating tax ID (#22569)

* Adding information about updating tax ID

Adding information about updating tax ID

* Update update-billing-info.mdx

Small correction of internal link

* Minor edits to align with style guide

---------

Co-authored-by: Denise Peña <[email protected]>

Author: simon-says

src/content/docs/billing/update-billing-info.mdx

@@ -57,3 +57,31 @@ Your billing email address is particularly important if you have [opted into ema
 3. Go to **Invoices and documents**.
 4. From **Billing email preference**, select **Change email address**.
 5. Enter and confirm your new email address, then select **Save**.
+
+## Add or change a Tax ID, VAT, or GST number
+
+If you added a payment method but did not include a Tax ID, VAT or GST number, you can add or change the Tax ID, VAT or GST number associated with the payment method afterwards.
+
+:::note 
+You cannot apply a VAT or GST number to past invoices. Adding a VAT or GST number will only apply to future invoices issued in the account.
+:::
+
+1. Log in to the [Cloudflare dashboard](https://dash.cloudflare.com) and select your account.
+2. Go to **Manage Account** > **Billing**.
+3. Go to **Payment**.
+4. From **Billing Address**, select **Edit**.
+5. In the **VAT/GST** field, enter your VAT or GST number.
+6. Select **Confirm**.
+
+## Remove a Tax ID, VAT, or GST number
+
+:::note 
+You cannot remove a VAT or GST number from past invoices. Removing a VAT or GST number will only apply to future invoices issued in the account.
+:::
+
+1. Log in to the [Cloudflare dashboard](https://dash.cloudflare.com) and select your account.
+2. Go to **Manage Account** > **Billing**.
+3. Go to **Payment**.
+4. From **Billing Address**, select **Edit**.
+5. In the **VAT/GST** field, delete the VAT or GST number.
+6. Select **Confirm**.