What is a negative database?
A negative database is a merchant's own record of card numbers, emails, addresses, and other identifiers tied to past fraud or chargebacks. Every new order gets checked against it before approval. Each confirmed fraud or dispute case adds another entry.
The list covers one merchant's own history, which is why merchants also call it a blacklist.
How a negative database works
A negative database compares each new order against stored entries, then flags or blocks any order that matches. The check runs at checkout or during order review, before you approve anything.
The comparison happens field by field. The US Payments Forum lists flagged card numbers, compromised account details, and high-risk customer records. Addresses and phone numbers count too.
If any one field matches, the order gets declined or held for review. So merchants store the email, billing address, device ID, and IP alongside the card number.
Our guide to blacklisting customers on Shopify shows the store-level setup.
Picture a customer who disputed a charge with you last month.
She orders again from the same address, but with a new card. If your list tracks addresses, that order still gets flagged.
A negative database catches only what it already holds. A first-time bad actor passes through clean, and so does a repeat one who arrives with a new card, email, and address.
Why negative databases have limits
A negative database protects only the merchant that built it, because you only ever recorded your own orders. Merchants can't fix that by swapping lists. Payment provider payabl. says ecommerce businesses cannot maintain any such "global blacklist." Customer IDs, phone numbers, emails, and home addresses count as private data.
So a bad actor you blocked can order freely from the next store. Your entries stay yours, and that store's stay theirs.
Two setups do reach further, and neither is a shared customer list. A fraud-prevention vendor can check an order against signals from its other clients. Those clients signed data agreements that allow it. Card networks run alert programs on dispute records instead.
For a signal that reaches past your own orders, our chargeback alerts work at network level.
Run your own repeat-disputer count through our ROI calculator to see what a list that only covers your own store is still missing.
How a negative database compares to related terms
A negative database runs on a single merchant's data, and the four terms below all operate at network level. Here's how each one differs:
FAQ
Is a negative database the same as a blacklist?
Yes, the two terms describe the same thing, and merchants use them interchangeably. "Blacklist" is the everyday word for it and "negative database" is the payments-industry term.
What information does a negative database typically store?
Card numbers, emails, phone numbers, billing and shipping addresses, device IDs, and IP addresses. Start with email, billing address, and device ID, since those catch the most repeats.
Do negative databases stop chargebacks?
They stop repeat orders from a customer you already flagged, so they prevent the second chargeback. The entry only exists because a first dispute already happened.
Negative database vs. chargeback alert
A negative database blocks a future order before approval, while a chargeback alert flags a dispute already filed on a completed sale. One works before the sale and the other after it.
