6. Checkout validation rules

A validation rule stops a buyer from continuing when your conditions match, and shows them your message.

Go to Rules → Add rule → Checkout validation.

6.1. Order limits and address checks

Order limits and Address are two groups of validation rules with ready-made starting points. On Rules, click Use a template on their cards, or Start from scratch.

Group	Examples
Order limits	Minimum order value, Maximum quantity per order, Maximum order weight
Address	Block PO boxes, Require a house number, Block specific ZIP codes

6.2. The Action tab

• Target placement: the message appears either under a field as soon as the buyer leaves it, or when the buyer tries to continue.
• Error message: what the buyer reads. If your store uses several languages, write one message per language. A language left empty uses your main language’s message.

👉 Tell the buyer what to change, not what went wrong: Add a street number to your address works better than Invalid address.

6.3. Example: Require a house number

1. On Rules, click Use a template on the Address card and pick Require a house number. The rule checks whether Address line 1 contains a number.
2. Set the error message, for example: Please add a house or building number to your shipping address.
3. Save the rule with its status set to Active.

The buyer can’t continue until they correct the address.

6.4. Safety warning

Important: An active validation rule with no conditions would run on every cart, and nobody could check out. The app asks you to confirm (Save anyway or Keep editing). Home also warns you whenever a validation rule is active.