Description

Accept credit cards, Apple Pay, and Google Pay seamlessly using the Gain Commerce NMI Payment Gateway for WooCommerce.

Engineered natively for WooCommerce Checkout Blocks and High-Performance Order Storage (HPOS), this plugin tokenizes cardholder data via NMI Collect.js—offloading PCI compliance away from your web server while providing a frictionless checkout experience.

Why Choose Gain Commerce NMI Payment Gateway for WooCommerce?

One-Click Mobile Checkout: Native support for Apple Pay and Google Pay to boost mobile conversions.
Zero PCI Friction: Uses NMI Collect.js tokenization—card data never touches your web server.
Modern Checkout Ready: Built natively for WooCommerce Checkout Blocks and traditional legacy checkouts.
Bot & Card-Testing Defense: Built-in protection via Google reCAPTCHA v3 or Cloudflare Turnstile to block automated attacks.
Built-in Surcharging: Offset transaction costs by adding flat or percentage-based credit card surcharges directly at checkout.

Free Features

Express Digital Wallets: Native support for Apple Pay and Google Pay.
PCI-DSS Compliant Tokenization: Secure Collect.js integration ensures zero sensitive card storage on your server.
Bot Defense: Block card-spinning scripts using Google reCAPTCHA v3 or Cloudflare Turnstile.
Credit Card Surcharges: Automatically pass processing fees to buyers via flexible flat or percentage rules.
Full Order Dashboard Control: Process Authorize, Capture, Partial/Full Refunds, and Voids directly from the WooCommerce order screen.
Card Brand Restrictions: Restrict or allow specific card brands (Visa, Mastercard, Amex, Discover) based on your merchant agreement.
Fraud & Ledger Sync: Log AVS/CVV response codes to order notes and auto-sync WooCommerce shipping data to NMI.
Dynamic Descriptors: Set custom statement descriptors passed directly to customer credit card statements.

Supercharge Your Store with Premium Features

Upgrade to the Gain Commerce NMI Premium Add-on to unlock recurring revenue and enterprise vaulting tools:

WooCommerce Subscriptions: Automated recurring payments and renewal order processing.
NMI Customer Vault: Stored payment methods allowing returning customers one-click checkouts.
ACH Electronic Checks: Direct bank transfer processing alongside credit cards.
3D Secure 2.0 (3DS2): SCA/PSD2 compliant step-up authentication for liability shift and fraud reduction.

System Requirements

Active NMI payment gateway account (via Allied Payments or your merchant account provider)
WooCommerce version 8.0 or higher
Valid SSL Certificate (HTTPS)
PHP version 7.4 or higher
Fully compatible with WooCommerce HPOS (High-Performance Order Storage) and WooCommerce Checkout Blocks

External Services

This plugin relies on external third-party services to process payments and prevent automated fraud:

NMI Payment Gateway (Network Merchants, LLC): Connects to NMI to securely tokenize card details in the browser via Collect.js before processing transactions. Order and shipping details are sent to NMI for transaction ledger processing.
- NMI Terms of Service
- NMI Privacy Policy
Google reCAPTCHA v3 (Optional): Evaluates checkout traffic to block automated card-testing attacks when enabled by the merchant.
- Google Terms of Service
- Google Privacy Policy
Cloudflare Turnstile (Optional): Provides CAPTCHA protection against automated card spinning when configured by the merchant.
- Cloudflare Privacy Policy

Source Code & Build Instructions

The source code for minified assets is available in the Gain Commerce GitHub Repository.

Build instructions:
1. Clone the repository.
2. Run npm install to install dependencies.
3. Run npm run build to generate production assets.

Screenshots

Gain Commerce/NMI settings page in WooCommerce — WooCommerce Checkout Page layout

Installation

Upload the gaincommerce-nmi-payment-gateway-for-woocommerce folder to /wp-content/plugins/, or search and install via Plugins > Add New in WordPress.
Activate the plugin through the Plugins menu.
Navigate to WooCommerce > Settings > Payments > Gain Commerce NMI Payment Gateway.
Enter your NMI API credentials (Private Security Key and Public Security Key).
(Optional) Configure Bot Protection (reCAPTCHA/Turnstile) and Credit Card Surcharging.
Set Environment to Live or Test Mode and save changes.

Testing Environment Setup

Enable Test Mode in gateway settings and use these standard NMI test card numbers:

Visa: 4111 1111 1111 1111
Mastercard: 5431 1111 1111 1111
American Express: 3411 1111 1111 1111
Discover: 6011 0009 9130 0009
Expiration Date: Any valid future date (e.g., 12/28)
CVV Code: Any 3 digits (4 digits for Amex)

FAQ

Does this plugin require a WooCommerce installation?: Yes. WooCommerce 8.0 or higher must be installed and active on your WordPress site.
Does this plugin require an active NMI account?: Yes. An active NMI payment gateway account is required. Contact Allied Payments, our preferred provider, to set up your merchant account.
Is this plugin PCI Compliant?: Yes. Utilizing NMI’s Collect.js script to tokenize payment data in the browser, sensitive credit card numbers never touch or pass through your web server, keeping your store fully PCI-DSS compliant.
Is an SSL Certificate required?: Yes. A valid SSL certificate is required on your website to maintain PCI-DSS compliance and ensure end-to-end security during customer checkout.
Does the free plugin store customer credit card details?: No. Credit card numbers are tokenized in real time by NMI and are never stored on your WordPress server. Storing cards securely in the NMI Customer Vault for returning customers is available when paired with our Premium Add-on.
How does credit card surcharging work?: You can enable surcharging in gateway settings to pass a flat fee or a percentage-based processing charge to your customers at checkout. The fee dynamically updates on the checkout page so customers see a transparent disclosure before placing their order.
How does bot protection defend against card testing?: You can supply your own Google reCAPTCHA v3 or Cloudflare Turnstile API keys in the settings. Once enabled, the system automatically checks checkout attempts to block automated card-spinning scripts from testing stolen card lists on your store.
Where can I get support or integration assistance?: You can visit our official support portal at gaincommerce.com/support for documentation and help desk assistance.

Reviews

There are no reviews for this plugin.

Contributors & Developers

“Gain Commerce NMI Payment Gateway for WooCommerce” is open source software. The following people have contributed to this plugin.

Gain Commerce

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Interested in development?

Browse the code, check out the SVN repository, or subscribe to the development log by RSS.

Changelog

1.16.6

Fix PHP warning “Undefined array key “default”” shown at the top of admin pages, and written to the PHP error log, until the gateway settings were saved for the first time. The warning also pushed the footer into the middle of the WooCommerce settings screen.
Change the gateway to be enabled by default until the settings are first saved. Sites that have already saved their gateway settings are not affected.
Change Test Mode to be off by default until the settings are first saved. Sites that have already saved their gateway settings are not affected.
Fix the WooCommerce Checkout Block not using the “enabled” default before the gateway settings were first saved.
Add a “Get Enterprise” link on the Plugins screen. It is hidden when the Enterprise add-on is active.

1.16.5

Add optional Bot Protection setting (Google reCAPTCHA v3 or Cloudflare Turnstile) to help block automated card-testing (“card spinning”) attempts at checkout. Disabled by default.
Add dynamic surcharge label to the Credit Card payment option at checkout — shows “(Includes $X surcharge)” or “(Includes X% surcharge)” based on the configured Processing Fee, updating automatically with the fee setting.
Rename the “Processing Fee” settings section to “Credit Card Surcharge” with updated description text.

1.16.4

Change card processing fee setting to a dropdown: No Processing Fee, Percentage Fee, or Flat Rate Fee.
Add flat rate processing fee option, in addition to the existing percentage-based fee.
Add live card-type highlighting at checkout: as the customer types their card number, the accepted-card icons narrow down to the matching brand.
Improve the Restrict Card Types setting to use a proper multi-select picker with clear “click to remove” tags, and clarify that leaving it empty accepts all card types.
Fix card processing fee not being applied on the WooCommerce Checkout Block (it previously only appeared on the classic checkout).
Fix new card entry occasionally resetting mid-checkout on the Checkout Block, caused by the Apple Pay / Google Pay amount sync re-initializing the card fields more often than necessary.

1.16.3

Fix extra blank space shown on checkout below the saved payment method option.
Fix card type icons to display as real card logos instead of text placeholders.
Fix Apple Pay / Google Pay showing the original cart total after a coupon, shipping change, or fee updated the order total.
Add optional card processing fee (percentage-based surcharge) for card payments, configurable in gateway settings.
Improve Apple Pay / Google Pay reliability so wallet payments are still recognized correctly even if a supporting script fails to load.

1.16.2

Updated with WordPress Latest Version

1.16.1

Fix issue on JS checkout both legacy and block.
Maintenance

1.15.1

Fix issue in NMI timeout

1.14.8

Support NMI Digital wallet payment, Google Pay and Apple Pay.

1.13.1

Add WooCommerce Subscriptions support for automatic recurring payments. Requires WooCommerce Subscriptions plugin and Premium Add-on.
Maintenance

1.12.0

Fix checkout issue in loading NMI in legacy and block base.
Fix UI fields in checkout page both in legacy and block base.
Maintenance.

1.11.0

Added support for 3D Secure (3DS) authentication when the Premium Add-on plugin is installed. The free plugin now enables 3DS for enhanced security, but requires the Premium plugin to activate this feature.

1.10.0

Fix and replace deprecated reduced_stock_qty to wc_reduce_stock_levels
Add ability for customers to store payment method for future transactions in card vault by choosing “Save Payment Method” during checkout. Available only in Premium Plugin
Choose “Saved Payment Method” stores card account in secure PCI-Compliant environment. Customer can replace card in checkout process by choosing “Save Payment Method”.
Test to latest WooCommerce version 10.4.3

1.8.1

Test to latest WordPress 6.9 version.
Test to latest WooCommerce 10.4.2
Add Description for premium plugin in readme file.

1.8.0

Add Shipping Fields from WooCommerce order to NMI merchants.
Ability to enable Dynamic Descriptor and pass descriptor data.
Add AVS/CVV notes in order.
Add additional order notes as Response code and NMI payment status.

1.7.6

Integrate restrict card type in block checkout
Integrate restrict card type in legacy checkout
Integrate CollectJS into WC checkout blocks
Integrate WC blocks
Add CollectJS to legacy checkout
WooCommerce Legacy checkout work on NMI
Add Auth Feature and when changed to order processing or complete then capture
Add Gateway Class
Add Logger Class
Add API class for NMI
Add API Factory
Add API Credit Card Sale
Add API Refund
Add API Void
Add API Auth, Capture and Auth + Capture

1.0.0

Initial release