Halt now removes card-testing bots from email lists
LAS VEGAS, NV, September 29, 2026
Native Code has updated Halt: Card Testing Blocker so it removes card-testing bots from a store’s email list. When Halt stops a bot at checkout, it now takes that contact off Shopify Email or Klaviyo, usually within minutes. The update is live for every store and included at no extra charge.
Halt: Card Testing Blocker now removes card-testing bots from a store’s email list. The update is live for every store that uses Halt, and it is included at no extra charge.
Card testing is when a bot runs stolen card numbers through a store’s checkout to find the ones that still work. Halt already stops those checkouts before the card is charged. This update deals with what the bot leaves behind.
The part nobody budgets for
Every bot also types an email address. Shopify keeps that address as a contact, even when the checkout is stopped or abandoned.
The store is then sending abandoned cart emails and newsletters to addresses that are fake. That costs in two ways. Mail to fake addresses bounces or gets ignored, which hurts a store’s sender reputation. Klaviyo and others charge by the number of contacts, so a store pays to keep bots on a list.
One merchant told us this was the part of a bot attack that cost them the most. That feedback is why this update exists.
“Every bot leaves an email address behind, and the store keeps paying for it long after the attack stops,” said the founder. “Stopping the checkout was only half the job. This is the other half.”
What the cleanup does
When Halt stops a bot at checkout, it now takes that contact off the store’s email list, usually within minutes.
| Email list | How a store connects it | What Halt does |
|---|---|---|
| Shopify Email | One button, and one permission from Shopify | Unsubscribes the contact and tags it halt-bot |
| Klaviyo | The store pastes a key | Suppresses the contact |
| Any other tool | Nothing to connect | The halt-bot tag in Shopify lets the store filter those contacts out |
How it protects real customers
The cleanup is built so a store owner can undo anything it does.
- Off until the store turns it on. Halt removes nothing from any list until the store owner presses Connect.
- Only while protection is on. In watch mode Halt records what it sees and removes nothing.
- Everything can be undone. Restore puts a contact back with one click.
- Nothing is hidden. Every removal is listed on the Removals page, and the history is kept.
- Existing settings are untouched. The update did not change any store’s rules.
Also in this release
- A Removals page. Every contact Halt removed, with the date, the list and the reason. One click on Restore puts a contact back and adds them to Always allow, so they are never stopped again.
- A country picker. Stores that ship to certain countries used to type two-letter codes by hand, and mistakes were common. Countries are now picked from a list, the way Shopify’s own shipping settings work. A code typed wrong in the past is marked so the store can fix it.
- Full addresses in Activity. The Activity page now shows the email address of each stopped checkout. A store owner can recognize a real customer and allow them with one click.
- A Notifications page. All email settings moved off the Rules page: where alerts go, the attack alert, and the daily summary.
What Halt is seeing
In the 24 hours before this update went live, Halt stopped more than 3,000 bot checkouts across the stores that use it. In the same 24 hours it watched more than 3,000 more on stores that have protection switched off and are still deciding.
Halt runs a suite of 140 automated tests before every release.
What is coming next
Attack detection is coming soon. Halt will spot a burst of checkouts on one product, from many different emails, with nobody buying. It will tell the store owner and turn those checkouts away. It is being tested now.
Price and availability
Halt is $6.99 a month with a 14-day free trial, and it is free on development stores. This update is included at no extra charge.
A store already running Halt can open the app, go to Rules, find Email list and press Connect. A new store can install Halt from the Shopify App Store, free for 14 days.