What is a community blacklist?

A shared signal built from reports submitted by many stores. At checkout the shopper's email or phone is checked against those reports, and you decide how many independent reports are required before a block.

Does it prove someone committed fraud?

No. It is a probability signal, not evidence. Reports describe one merchant's experience, so you use it with a threshold you are comfortable with.

How many reports should I require?

High-value, easily resold products justify a lower threshold. Low-margin, high-volume stores should require more reports before refusing a sale.

Is it worth it for a new store?

It is most valuable for a new store, because your own blocklist is empty and this is the only signal that works on a first-time visitor.

How a community blacklist works

Updated September 22, 2026 · 4 min read

Every blocking rule you write has the same blind spot: it needs the damage to have already happened to you. A community blacklist answers a question your own data cannot — has this person burned other stores?

How it works

A merchant reports an identifier. A store that took a chargeback reports the email address or phone number involved.
Reports accumulate independently. The same identifier reported by five unrelated stores means something very different from one report.
Your checkout asks the question. When a shopper checks out, their email or phone can be checked against those reports. You choose which checks run.
Your threshold decides. You set how many reports are required before a checkout is blocked. Below it, the checkout goes through untouched.

Setting the threshold

There is no universal number, because the cost of being wrong differs by store. A blocked genuine shopper is a lost order; an accepted fraudster is a lost product plus a lost payment plus a fee.

Threshold	Behaviour	Fits
Low	Aggressive — blocks on a weaker signal	Electronics, sneakers, luxury: high value, easily resold
Medium	Requires corroboration from several stores	Most stores. Start here
High	Only heavily reported identifiers are blocked	Low-margin, high-volume stores

Start conservative and watch the interception log for a few weeks. If the blocks look right, lower it. A threshold you tuned on your own data is one you can defend when a customer calls to ask why their order failed.

What it is not

Not proof of fraud. A report can reflect a delivery failure or a dispute the customer was right to raise.
Not an identity or credit check. It says nothing about a person beyond how often that identifier was reported.
Not a replacement for your own rules. Someone who has only ever defrauded you appears in no shared list.
Blind to brand new identifiers. A fresh email has no history anywhere.

Turn on the community check, set the number of reports you trust, and stop repeat offenders on their first visit to your store.

Install Chargeback Blacklist

What covers the blind spot

Because a brand new email is invisible to any shared list, the community check works alongside the app's repeat-attempt protection. Once any checkout is blocked — by a community match or one of your own rules — the device fingerprint and IP address behind it are banned. Changing the email, phone or name afterwards does not get them back in. The honest limits of that are worth five minutes.

Privacy, in plain terms

You are handling other people's personal data. The useful output is whether an identifier has been reported often enough to cross your threshold, not another store's customer list or order history. Before enabling any shared signal, read the app's privacy terms, check it fits the privacy rules in your market, and make sure your own privacy policy mentions the fraud screening you run at checkout.

Who benefits most

New stores. Your blocklist is empty, so borrowed history is the only history you have.
Digital or instant delivery. No shipping address to block and no delay to catch the order.
High-value resellable goods. The categories organised fraudsters target.
Stores that just took their first chargeback. Start with auto-blocking past chargeback customers.

The community check is available on the higher plans, and you choose whether it runs on emails, phone numbers, or both.

FAQ

What is a community blacklist?: A shared signal built from reports submitted by many stores. At checkout the shopper's email or phone is checked against those reports, and you decide how many independent reports are required before a block.
Does it prove someone committed fraud?: No. It is a probability signal, not evidence. Reports describe one merchant's experience, so you use it with a threshold you are comfortable with.
How many reports should I require?: High-value, easily resold products justify a lower threshold. Low-margin, high-volume stores should require more reports before refusing a sale.
Is it worth it for a new store?: It is most valuable for a new store, because your own blocklist is empty and this is the only signal that works on a first-time visitor.