How Blocking Works in Antifraud: A Complete Guide for Shopify Merchants

Running a Shopify store means dealing with visitors from all over the world. While most are genuine customers, some bring unwanted risk — fraudulent orders, chargebacks, scrapers, or simply traffic from regions where you don't ship. That's where Antifraud's blocking system comes in.

This guide will walk you through how block rules work, how the priority system protects your legitimate customers, and how to set everything up correctly.

What Are Block Rules?

Block rules prevent visitors from accessing your store entirely. When a visitor matches a block rule, they cannot view your products, add items to their cart, or complete a checkout.

Instead of seeing your storefront, blocked visitors will see one of the following:

• A custom Access Denied message that you can fully customize with your own title, description, logo, and colors
• A blank page (if you prefer not to display any message)

This is the most aggressive level of protection. Unlike redirects (which send visitors elsewhere) or whitelists (which guarantee access), block rules completely deny access — no exceptions for matching visitors.

When Should You Use Block Rules?

Block rules are ideal when you want to keep certain visitors out of your store entirely. Common use cases include:

• Countries you don't ship to — there's no point letting visitors browse if you can't fulfill their orders
• High-risk regions — countries known for high chargeback rates or fraud activity
• Regulatory restrictions — places where your products cannot be legally sold
• Suspicious traffic sources — referrer URLs from scraper sites or spam networks

If you only want to redirect visitors to a different store or page instead of blocking them outright, use Redirect rules instead. If you want to ensure trusted visitors are never blocked, use Whitelist rules.

The Priority System: How Antifraud Decides Who Gets Through

When a visitor lands on your store, Antifraud checks them against your rules in a specific order. Understanding this priority is essential — it's how Antifraud prevents accidental blocking of legitimate customers.

The order of priority is:

1. Whitelist rules (highest priority — always allow)
2. Block rules (deny access)
3. Redirect rules (send to another URL)
4. Default allow (no rule matched — visitor passes through)

Why Whitelist Always Wins

The whitelist has the highest priority because it acts as your safety net. If a visitor's country is on your whitelist, they will always be allowed through — even if that same country is also on your block list.

Here's a practical example:

Imagine you block the entire country of Vietnam because most of your fraud orders come from there. But your warehouse partner is based in Ho Chi Minh City and needs to access your store daily. Without a whitelist, they'd be blocked along with everyone else.

By adding their specific country (or in future versions, their specific IP) to the whitelist, you guarantee they always have access — no matter what other block rules you create.

This priority system prevents two common problems:

• Accidentally blocking legitimate customers — you can be aggressive with block rules knowing the whitelist will protect your trusted visitors
• Conflicting rules — when rules contradict each other, the whitelist is always the deciding factor

How to Set Up Your First Block Rule

Setting up a block rule in Antifraud takes less than a minute. Here's the step-by-step process:

Step 1: Open the Antifraud app in your Shopify admin and go to the Rules page.

Step 2: Make sure the Block tab is selected at the top.

Step 3: Click + Add rule to open the rule creation form.

Step 4: Choose how you want to block:

• Block specific countries — select countries to BLOCK (all other countries will be allowed). Use this when you only want to block a few specific regions.
• Block all except — select countries to ALLOW (all other countries will be blocked). Use this when you only sell to a few regions and want to block everywhere else.

Step 5: Search and select the countries from the dropdown. You can add multiple countries to a single rule.

Step 6: Make sure the rule status is set to Active.

Step 7: Click Save.

Your rule is now live. Any visitor from a matching country will immediately see your Access Denied page when they try to access your store.

A Word of Caution

Block rules are powerful, but they're also a blunt instrument. Before you start blocking entire countries, ask yourself:

• Are you sure you don't have legitimate customers there?
• Could a redirect to a localized store work better?
• Have you whitelisted any team members or partners who need access from those regions?

Many merchants make the mistake of blocking aggressively and only realize months later that they've been turning away thousands of dollars in legitimate sales. The whitelist exists specifically to prevent this — use it generously to protect the visitors you trust.

Wrapping Up

Antifraud's blocking system is designed to give you control without complexity. The three-tier priority — whitelist, then block, then redirect — gives you a safety-first approach to fraud prevention that's hard to mess up.

Start small. Block one or two high-risk countries. Add your trusted partners to the whitelist. Watch how it performs for a week, then expand your rules from there.

If you have questions or run into any issues, our support team is just a click away inside the app.

Updated on: 11/06/2026