A complete guide: Block Checkout
Overview
Stop fraudsters at checkout, before they turn into orders you have to cancel or refund. With Block Checkout, when a shopper's details or connection match one of your rules, Shopify stops the checkout and shows your error message instead of creating the order. You set up the rules in the Block Checkout tab in Blockify. Shopify itself runs Blockify's checkout check, so your rules also cover express checkouts and customers who switch device.
What you'll learn
- Two ways to block a checkout
- How to activate Block Checkout in Shopify?
- Add Blockify checkout blocks (Shopify Plus)
- Quick Setup
- How to copy your store rules to checkout?
- How many checkout rules can I add?
- What the Overview cards show
- Who can use this feature?
Two ways to block a checkout
The Block Checkout page has two tabs. They block different things and need different plans.
Tab | What it checks | What you can block by | Plan |
|---|---|---|---|
Block checkout access | Who is visiting and where they connect from, as soon as the checkout page opens | IP address, Location, User agent, ISP, VPN/Proxy | Shopify Plus plan (needs the Blockify checkout block in the checkout editor) |
Block checkout fields | The details the shopper types into the checkout form | Email, Phone number, Name, Country, Address, Zip code, Customer tag | Enterprise plan and above |
- Set up access rules in Block checkout access by IP, country or VPN (Shopify Plus). Shopify Plus stores must first add the checkout block: see Add Blockify checkout blocks (Shopify Plus).
- Set up field rules in Block checkout by email, phone, name, address or customer tag, and change the message shoppers see in Customize the checkout error message.
Both tabs stop the checkout and show a message; neither cancels or refunds orders that were already placed. To stop many checkouts in a row that reuse one email, address, phone or name, use Stop repeated checkout attempts in Fraud Filters.
How to activate Block Checkout in Shopify?
Before any Block Checkout rule can work, you need to turn on Blockify's checkout rule in your Shopify admin. You only do this once.
Step 1: Open the Checkout rules section
In your Shopify admin go to Settings > Checkout and scroll down to Checkout rules.
Step 2: Add the Blockify rule
Click Add rule and select Block Checkout by Blockify.
Step 3: Save and turn the rule on
Tick Allow all customers to complete checkout, click Save, then Turn on.
Step 4: Create your first rule in Blockify
Back in Blockify, open Block Checkout, choose the tab you need and click Create rule.
Add Blockify checkout blocks (Shopify Plus)
Block checkout access rules (IP address, Location, User agent, ISP, VPN/Proxy) work on Shopify's checkout page itself, so Shopify Plus stores must also add the Blockify - Checkout UI app block in the checkout editor once. Without the block, your access rules are saved but never block anyone. Block checkout fields rules don't need it.
Step 1: Open the theme editor
In your Shopify admin go to Online Store > Themes and click Customize.
Step 2: Switch to the checkout page
Open the page menu at the top and select Checkout page.
Step 3: Add the Blockify app block
Click the Apps icon in the left sidebar (below the settings icon), find Blockify - Checkout UI and click Add app block.
Step 4: Allow the app to block checkout
Click the Blockify - Checkout UI block you just added and tick Allow app to block checkout.
Step 5: Save and test
Click Save. Open your store, start a checkout that matches one of your access rules and check that the error message appears.
Quick Setup
Quick Setup sits at the top of the Block Checkout page. Each checkbox turns on a ready-made protection, so you don't have to create a rule yourself.
Checkbox | What it blocks | Guide |
|---|---|---|
Auto-block creating orders with a subtotal of 0 and matching last name with first name. | Checkouts whose subtotal is $0 (before shipping and taxes) and whose first and last name are identical | |
Auto-block creating orders with a subtotal of 0 and different first and last name. | Checkouts whose subtotal is $0 and whose first and last name differ | same guide |
Auto-block IP from high-risk orders at checkout | Every new checkout from the IP of an order that Fraud Filter flagged as high-risk. Requires Fraud Filter to be enabled. Shopify Plus only. | Auto-block IP from high-risk orders at checkout (Shopify Plus) |
Block checkout from disposable or temporary email addresses | Checkouts entered with an email from a disposable provider such as 10minutemail or mailinator |
The Error message field under Quick Setup is the text shoppers see when one of these protections stops them. The default is "Order cannot be placed due to suspected fraud." and it cannot be blank.
How to copy your store rules to checkout?
Want visitors you already block on your store to be stopped at checkout too? You don't need to create each rule again. On the Block checkout access tab (Shopify Plus), click the refresh icon with the tooltip Sync rules above the rule table. Blockify copies your active Block & Re-director > Blacklist rules into Block checkout access: IP address, location, user agent and ISP rules. Product, collection, page and referrer URL rules are not copied. A message confirms the update.
How many checkout rules can I add?
Shopify limits how much rule content Blockify's checkout check can hold, counted in characters. The Checkout validation usage counter on the Block Checkout page shows how much of that limit your rules use, as x / y characters, with a colour:
Status | Meaning | What to do |
|---|---|---|
Green | You have plenty of room left | All rules work normally; you can keep creating rules |
Amber | You're close to Shopify's limit | Review or remove rules you don't use; adding a rule may make existing rules stop working |
Red | You've reached Shopify's limit | You cannot create new rules, and Blockify's checkout check stops working on your store until you remove some rules |
What the Overview cards show
The Overview at the top of the Block Checkout page sums up what your checkout rules stopped in the period you pick.
Card | How it is calculated | How to read it |
|---|---|---|
Total blocked orders | Checkout attempts stopped by a checkout rule — attempts, not completed orders | Fake checkouts caught before they turn into orders you would have to refund |
Block rate | The share of all checkout attempts in the period that were blocked | A sudden jump means an attack; a slow climb means your rules may be too strict |
Estimated savings | Cart value of blocked checkouts that were never completed | The most you could have lost — it assumes every blocked checkout would have been fraud |
Who can use this feature?
- Block checkout fields and Quick Setup: available on the Enterprise plan and above.
- Block checkout access, the Blockify - Checkout UI checkout block and Auto-block IP from high-risk orders at checkout: available on the Shopify Plus plan.
FAQs
- A shopper matched a rule but the order still went through. Why?
Check three things: the Block Checkout by Blockify rule is turned on in Settings > Checkout > Checkout rules; the Checkout validation usage counter is not red; and, for Block checkout access rules, the Blockify - Checkout UI block is added with Allow app to block checkout ticked and your rule is turned on.
- Does Block Checkout cancel or refund orders?
No. It stops the checkout before the order exists and shows your error message. Orders that were already placed are handled by Fraud Filters, not by checkout rules.
- Do I need the checkout block for Block checkout fields rules too?
No. Email, phone, name, address and customer tag rules work through the Block Checkout by Blockify checkout rule in Settings > Checkout and don't need the app block. Only Block checkout access rules need it, which is why that tab is greyed out for stores that are not on Shopify Plus.
- Does the checkout block change how my checkout looks?
No. Shoppers don't see the block; it only lets Blockify stop a checkout and show your error message.
- Can I block abandoned checkouts?
No. Shopify does not allow apps to act on abandoned checkouts.
- Where do I see which checkouts were blocked?
On the Block Checkout page Overview cards (Total blocked orders, Block rate, Estimated savings). There is no per-rule counter.
Updated on: 16/10/2026
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