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NMI Gateway


NMI Gateway

NMI is a provider of electronic commerce and payment solutions. 

Supported Payment Methods

The NMI Gateway supports the following payment methods:

  • Credit Cards, including
    • Visa
    • MasterCard
    • American Express
    • Discover
    • Diners
    • JCB
  • ACH

Supported Payment Operations

The following payment operations are available through NMI:

  • Payment Method Creation (zero and positive default authorization amount)
  • Payment creation (sale)
  • Payment refund (referenced)
  • Payment credit (non-referenced refund)
  • Payment cancelation

The NMI payment gateway integration does not support payment reconciliation.

Stored Credential Transactions

NMI gateway integration includes support for the Stored Credential Transactions framework. For details about the supported payment methods, see Support for stored credential transactions overview.

Configure the NMI Payment Gateway


  • Receive an account gateway account from your merchant services provider
  • Configure the payment gateway settings using the merchant account credentials. These credentials are used for the API calls in each payment operation.


  1. Navigate to Settings > Payments > Setup Payment Gateway.
  2. Click Gateway Type field and select NMI.
  3. Click create gateway.
  4. Specify field values.
  5. Click save gateway information.

Common Gateway Configuration Fields

There are some common fields you must complete for every gateway configuration. We recommend reviewing Setting Up Payment Gateways for information on these fields: 

  • Name

  • Use Gateway Test Environment

For the NMI Gateway the Use Gateway Test Environment is unique in that it does not actually enable the testing environment for the gateway. In order to monitor their test transactions the customer will have to enter the merchant portal and enable Test Mode for their transactions (Settings > Test Mode > ‘Enable Test Mode’). It is best practice to check this setting if the test mode is enabled in the merchant portal.

  • Cards Accepted

  • Default Authorization Amount

The value for this field must be greater than or equal to 1.00 if the customer intends to on performing an authorization void. Otherwise, if the customer wants to do a validation without an authorization amount, then they would set this value to 0.

  • Verify new payment method (required)

  • Verify updated payment method (optional)

NMI Gateway Configuration Fields

In addition to the common fields, you must provide the following field values that are specific to the NMI gateway. The fields are required:

  • Username: The username for the customer’s merchant portal. The username is required for all API calls.

  • Password: The password associated the username for the merchant account. This is required to authenticate all API calls.


  • The NMI gateway does not have different endpoints for test and production. In order to use a test account, a customer will have to go to their merchant control panel (Settings > Test Mode > ‘Enable Test Mode’).

  • The Use Test Gateway setting does not impact this gateway because enabling the testing environment is driven by the credentials and settings in the Merchant Portal

  • By default, all gateway accounts have a duplicate threshold setting of 1200 seconds (20 minutes). This time period can be adjusted, overridden, or turned off completely. Customers will have to contact their merchant service provider to adjust this setting.