How do I block a phone number at Shopify checkout?

Shopify admin has no phone blocking setting. In Chargeback Blacklist you create a rule of type Phone, enter the number, and checkouts using it are refused before payment.

What format should I enter the number in?

Enter it the way it appears on the order, and add the international form such as +15550123456 as a second rule if you sell across borders.

What if my checkout does not collect a phone number?

Then a phone rule has nothing to match. In Shopify admin under Settings, Checkout, set the shipping address phone number to required, and rely on email and address rules meanwhile.

Is phone better than email?

It is stickier. A new email is free and instant; a new number costs money or a virtual number service. Neither is enough alone.

Block a customer by phone number

Updated September 22, 2026 · 3 min read

Blocking is a contest of replacement cost. A new email takes fifteen seconds and costs nothing. A new phone number costs money. That is the whole argument for phone rules — and couriers often require a real number, so the person who wants the parcel has a reason to give one.

First, check you collect phone numbers

A rule can only match a field that exists. Many stores never see a number because checkout does not ask, and merchants discover this only after a rule never fires. In Shopify admin open Settings → Checkout and set the shipping address phone number to required if your couriers need it.

Create the rule

Copy the number from the order in Shopify admin, country code included.
In Chargeback Blacklist, add a rule, choose Phone, paste, save.
If you sell internationally, add a second rule with the same number in +15550123456 form.
Pair it with the email and address from the same order.

Formatting is where phone rules fail

These are all the same number to a human, and not to a text match:

+1 555 012 3456
(555) 012-3456
555-012-3456
0015550123456

Copy the version stored on the order rather than one from a phone call. Returning customers type their number the same way every time, especially when the browser autofills it.

Add the number they cannot regenerate for free, alongside the email and address from the same order.

Install Chargeback Blacklist

If they swap the number

Some will type a fake number or leave the field blank. That is covered by a different layer: the first blocked checkout bans the device fingerprint and IP address behind it, so the retry is stopped even when every field on the form is new. Changing the identifiers is not enough — they would also need a different browser or device and a different network.

Numbers reported by other stores

Your own rules only know numbers that already caused you a problem. The community blacklist can check a phone number against reports from other merchants, with a threshold you control, so a number that is new to you but reported repeatedly elsewhere can be stopped on the first attempt.

Two things to check before saving

Shared business numbers. Blocking a company switchboard blocks everyone who works there. Search your orders for that number first.
Households and resellers. If the number appears under several names, block the specific name or tag the customer record instead.

Do not block an area code or prefix. It catches large numbers of legitimate customers for very little gain.

FAQ

How do I block a phone number at Shopify checkout?: Shopify admin has no phone blocking setting. In Chargeback Blacklist you create a rule of type Phone, enter the number, and checkouts using it are refused before payment.
What format should I enter the number in?: Enter it the way it appears on the order, and add the international form such as +15550123456 as a second rule if you sell across borders.
What if my checkout does not collect a phone number?: Then a phone rule has nothing to match. In Shopify admin under Settings, Checkout, set the shipping address phone number to required, and rely on email and address rules meanwhile.
Is phone better than email?: It is stickier. A new email is free and instant; a new number costs money or a virtual number service. Neither is enough alone.