Beyond the address itself, AddressHero can validate the customer's first and last name and the characters used across the checkout form. Two rules are involved, and knowing how they interact saves you a support ticket.
💡 In short: The Name format rule (Pro plan) blocks identical first and last names, names shorter than two characters and symbols in the name fields. It uses the same character list as Block special characters, so any character you add there, including digits, is blocked in the address fields and in the name fields alike. Both rules run in the checkout, so they do not apply to express checkouts like Apple Pay, PayPal Express or Shop Pay.
Name format (name validation)
Enable the rule Name format under Settings > Checkout validation (Pro plan). With it active, AddressHero blocks the checkout when:
First and last name are identical, for example "John John" or "Test Test". Upper and lower case do not matter.
First or last name is shorter than two characters, for example a single letter.
First or last name contains a special character. The check uses exactly the same character list as the rule Block special characters (see below), so what counts as "special" is consistent across the whole form.
The customer sees the error message on the affected name field and cannot complete the checkout until the name is corrected. The error texts can be adjusted under Languages.
"Block special characters": symbols, not scripts
The special characters rule checks address line 1, address line 2 and city. Out of the box it rejects these symbols: { } [ ] ( ) ! @ $ % ^ & *. It does not touch accented Latin letters (é, ü, ñ), which are part of the Latin-1 range.
Adding your own characters. Use the field Add further special characters to block to extend the list, one character per entry, for example #, + or /. Everything you add is applied to the address fields and, when Name format is active, to the name fields as well.
ℹ️ Note: The character list cannot be configured per field. It is not possible to block a character in the name fields but allow it in address line 1. If you need per-field rules, tell us via support, it is on our list as a feature request.
Numbers in names
Digits are not blocked by default, neither in the address fields (a house number is a digit, after all) nor in the name fields. You could add the digits 0 to 9 as further special characters, but because the list applies to every checked field, this would also reject house numbers in the address lines. Blocking digits only in the name fields is therefore not possible today.
Non-Latin scripts (Japanese, Cyrillic and others)
By default, all characters outside the Latin-1 range are blocked, which includes Kanji, Kana, Cyrillic and Greek. This happens as part of the two rules above: in the address fields via Block special characters, in the name fields via Name format. Two things to check:
The setting "Allow non-Latin characters" must be switched off, because it overrides the block.
The block applies where the in-checkout validation runs. Orders via express buttons bypass the checkout and are only caught post-checkout (see Express wallets and landing-page checkouts).
There is no transliteration: AddressHero does not convert Japanese or other scripts into Latin letters for your carrier.
Good to know
Both Name format and Block special characters need the Pro plan.
The name rules are format checks in the checkout. The post-checkout validation verifies address components against reference databases and never touches names.
Like every in-checkout rule, the name rule needs the block permission in the Shopify checkout editor and only works for Shopify-integrated payment methods.
Express checkouts, such as Apple Pay, PayPal Express and Shop Pay, skip the regular checkout form entirely, so neither Name format nor Block special characters can run on them. Those orders are still validated post-checkout instead. See Express wallets and landing-page checkouts.
See Blocking invalid checkouts (Plus and non-Plus) for the permission and payment-method requirements.
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