With Shift4, you can prevent unwanted transactions from occurring. To accomplish that, you need to create a blacklist rule. Following are the details. 

Blacklist rules 

You can set the following rules:

• Card fingerprint
  All transactions coming from this specific card will be blocked if a block is set up based on the card fingerprint.

• IP address
  Allows stopping every transaction that originates from a certain IP address.

• IP country
  Enables blocking of all transactions coming from an IP address's designated country of origin.

• Metadata
  Blocks all transactions for the given metadata key or value.

• Email
  Blocks all transactions for a specific email address.

• User agent
  Blocks all transactions coming from the specified user agent.

• Accept language
  Blocks all transactions coming from the specified accept language value.

• Card country
  Blocks all transactions coming from the card's country of origin. 

• Card BIN
  Blocks all transactions originating from the given card BIN.

Adding a blacklist rule 

You can add a new blacklist rule when checking a charge or a customer and also from the dedicated Blacklist section. 

Charge view 

1. Click the charge that you want to block on the Charges list. 

2. To create a rule for a value, click the Blacklist button and choose a criterion for a blacklist rule. It is possible to choose more than one option.

3. Blacklist rule will be created instantly and removed if a box is unticked

4. Manage blacklist offers additional criteria such as: issuer, country, user agent, language.
   
   

Dispute view 

1. Navigate to the Charges list, then to dispute you'd like to process 

2. To create a rule for a value, click the Blacklist button. There are only two values for creating a blacklist rule form the dispute level - card fingerprint and issuer (available through Manage blacklist option)

3. Blacklist rule will be created instantly and removed if a box is unticked
   
   

Customer view 

1. Click the customer that you want to block on the Customers list. 

2. Click the Blacklist button next to a value that you want to set up a rule for.

3. There is only one value for creating a blacklist rule form a customer level - email

4. Once the box next to an email in the blacklist modal is ticked the blacklist rule is created instantly
   
   

Blacklist section 

1. Go to the Blacklist section. 

2. Click the Add blacklist rule button.

3. Select the rule type. 

4. Provide value for the rule type. 

5. Click the Add button to create the rule. 

Removing a blacklist rule 

You can remove a blacklist rule when checking a charge or a customer or from the dedicated Blacklist section. 

Charge view 

1. Click the charge that you want to remove a rule for on the Charges list.  

2. Click the Blacklist button next to a value from which you want to remove a blacklist rule.

3. Untick the box with a blacklisted value

Customer view 

1. Click the charge that you want to block on the Customers list. 

2. Click the Blacklist button next to a value from which you want to remove a blacklist rule.

3. Untick the box with the blacklisted email

Blacklist section 

1. Go to the Blacklist section. 

2. Find the rule that you want to delete on the Rules list. 

3. Click the Delete button.
   

4. Confirm the removal of the rule by clicking the Delete button.