One of the most important parts of the application setup is connecting a Credit Card and/or PayPal payment processor. OCU currently supports the following payment gateways:

*Important Notes:  

  1. Processing refunds for OCU orders requires you to to use either the 1-step or 2-step refund method gone over in our help articles. 
  2. Shopify Gift Cards will not work as a form of payment on the OCU checkout due to API limitations. However, you can offer Shopify Gift Cards as an upsell product if you'd like. 

Connect a Credit Card Payment Processor:

To connect a payment processor, from the left-side navigation menu go to Settings > Payments:

The default credit card processor is Stripe Connect. If you are not a Stripe user you can either sign up for a new account or change your credit card processor to one of the other supported ones by selecting it from the drop-down menu:

Note:  It is recommended to switch off all OCU funnels 1 hour prior changing your payment processor. This way all checkouts started with your current processor will be finished correctly. Then connect your new processor and switch the OCU funnels back on again. The OCU app needs to be disabled prior to changing your Credit Card processor.

Display only certain credit card Logos on the OCU checkout:

By default, all credit card logos are shown. You can choose specifically which credit card logos you want shown in-case your store only accepts certain ones. Just make your selections and click "Save".

Connecting Stripe Connect:

  • Click on the "Connect to Stripe" button
  • Click on the "Sign in with Stripe to connect" button on the next page. If you don't have a Stripe account, you can sign up for one here by clicking the "Sign up" link
  • Enter your Email address and Password and then click the "Sign in to your account" button
  • Click the "Connect my Stripe account" button on the next page
  • Click the "Enabled" switcher to the "On" position
  • Click on the "Save" button to store settings

Connecting Braintree:

*Important Note: Braintree is not opening any new accounts for use with OneClickUpsell at this time. This means that, if you are applying for a new Braintree account, applications that mention OneClickUpsell will not be accepted.  However, OCU fully supports existing Braintree accounts.

  • Enter your Merchant ID, Public Key and Private Key API credentials into the appropriate fields
  • Set "Gateway" to "Production"
  • Click the "Enabled" switcher to the "On" position
  • Click on the "Save" button to store settings

When using the Braintree processor there's an option to enable payments with a PayPal account at OCU checkout. Just make sure that option is enabled within your Braintree account first at Settings > Processing > Processing Options > PayPal:

Then within OCU, click the "Accept PayPal" switcher to the "On" position and Save.
The PayPal option will appear like this when on the OCU checkout page:

*Note: By default, OCU works with the Master Merchant account (default). If you have a multi-merchant account to work with different currencies, you need to enter the appropriate Merchant Account ID into the corresponding field in the OCU settings.

Connecting CIM:

If you haven't yet, you need to enable the Customer Information Manager (CIM) feature within your account. OCU uses that for the integration for This is a free service provided to you, so you just need to enable it by following the instructions here. 

  • Enter your API credentials into the appropriate fields. How do I find my API credentials?
  • Set "Gateway" to "Production"
  • Click the "Enabled" switcher to the "On" position
  • Click on the "Save" button to store settings


1) The Payment Form - Fields settings within your account actually have an affect on API transactions and all should be set as non-required.

To change these settings, login to your Authorize.Net account and go to Account > Settings > Payment Form - Fields and set all fields as non-required by un-checking any currently "Required" field names there. 

Don't worry about empty fields validation because all these fields are required on the OCU checkout.

2) We recommend to not enable the Transaction IP Velocity Filter in your account. If you do enable this filter, then we recommend to set the "Allow X transactions from the same IP address per hour." setting to a high number like 10 for example:

Otherwise, if you enable the filter and set the number of allowed transactions from the same IP setting to a low number, your account may see OCU order transactions as duplicates and decline the transactions.

3) In Tools > Fraud Detection Suite > Transaction Settings it's important to set either "Allow", "Allow, Report Triggered Filter(s)" or "Decline" but not "Authorize and Hold For Review" because we only support the Authorize and Capture method.

4) Authorize.Net considers the purchase of an upsell product that has the same cost as the main checkout purchase as a duplicated transaction

I.e. If the checkout transaction amount is $1 and the upsell offer product amount is also $1, sees that as a duplicate and denies it if enough time hasn't passed between transaction attempts. 

This is a restriction from's side that we're unable to control. Therefore, it's recommended to set a different price for the upsell offer product vs the initial checkout to prevent such an issue from occurring.

Connecting PayPal Website Payments Pro (US):

*Note: You will need a PayPal Business account to use this integration. Go to your PayPal Profile under My settings and verify that your Account Type is Business, or upgrade your account.

Follow the quick and easy steps below to create your app to get your Client ID and Client Secret.

1. Navigate to and click the "Log in to Dashboard" button: 

2. Once you are logged in to your PayPal account, go to the "My Account" section and make sure you have the following features enabled for REST API apps in the Live column:

3. Under the "My Apps & Credentials" section make sure to click into "Live" mode:

4. Scroll down to REST API apps and click the "Create App" button:

5. Enter the App Name (OneClickUpsell for example) and click on the "Create App" button:

6. Copy the keys from the Client ID and Secret fields:

7. Open the OneClickUpsell app from your Shopify admin and navigate to Settings > Payments > Direct Credit Card Processor.

  • Click the Processor dropdown menu to select "PayPal Payments Pro (US)".
  • Paste in your copied Client ID and Secret keys into the appropriate fields.
  • Click the switcher below "Direct Credit Card Processor" to enable the integration.

Connecting NMI:

NMI doesn't board merchants directly, rather they provide their software to Merchant Service Providers. The service providers then work directly with the merchants and board them. If you need a referral to a merchant service provider, contact NMI's sales team.  

  • Enter your Security Key into the appropriate field. It should be an API key or an API & Cart key.
    To find your key: From within your NMI dashboard, click on Settings in the left sidebar. Locate the section labeled Security Options and click on the Security Keys link. Click "Create New Key". Once the key has been created, copy it and paste it into the NMI section of the OCU app.
  • Set "Gateway" to "production"
  • Click the "Enabled" switcher to the "On" position
  • Click on the "Save" button to store settings

NOTE: NMI allows access to multiple merchant accounts through one login. By default, OCU works with the default Credit Card processor in your NMI account. If you have multiple CC processors in your merchant account, you need to enter the appropriate merchant Processor ID into the corresponding field in the OCU settings.

The Processor ID can be found within your NMI admin control panel by going to Home > List Merchants > Details > Configure Processor:

NOTE: OCU needs the Customer Vault to be set up within your NMI merchant account to function properly. This is the mechanism used for credit card storage so that we can charge your customers for the upsell/downsell offers. Contact your gateway provider to enable Customer Vault.

If it’s not set up, then OCU will not be able to create transactions. More information about the Customer Vault for NMI can be found here.

Additional Information (NMI Integration)

Sometimes the transaction amount for the upsell/downsell offer product(s) can be the same amount as the initial checkout purchase. In this case, NMI will recognize this purchase transaction as a duplicate and will decline it. To prevent this issue, un-check the Enable Duplicate Checking setting or set the Duplicate Threshold field to less than the default 1200 seconds.

The Duplicate Velocity Controls can be found within your NMI admin control panel by going to Home > List Merchants > Details > Configure Processor:

If you are going to leave the “Enable Duplicate Checking” setting enabled, we recommend to set the "Duplicate Threshold" field to 30 seconds. If 1200 seconds is set, your customers will not be able to purchase an upsell/downsell offer product if the transaction amount is the same as the initial checkout’s transaction amount.  

NOTE: E-check transaction are not allowed on the OCU checkout.

*IMPORTANT* Don’t forget to connect your live credentials within the OCU app when you are ready go live with your NMI account and start processing actual orders. NMI allows payments using real credit cards when the account is in test mode. If you do not connect your live credentials, the order will still be placed, but you wouldn’t actually receive the funds for it.

Below is the list of countries and card types each payment processor supports. Information about available locations was taken from these gateways' support pages and may not reflect their current offerings. For the most accurate information, contact the payment gateway:

  • Stripe = AT, AU, BE, BR, CA, CH, DE, DK, ES, FI, FR, GB, HK, IE, IT, JP, LU, MX, NL, NZ, NO, PT, SE, SG, US
    Supported Card Types = Visa, MasterCard, American Express, Discover, JCB, Diners Club, Maestro
  • Braintree = AD, AT, AU, BE, BG, CA, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GG, GI, GR, HK, HR, HU, IE, IM, IS, IT, JE, LI, LT, LU, LV, MC, MT, MY, NL, NO, NZ, PL, PT, RO, SE, SG, SI, SK, SM, US
    Supported Card Types = Visa, MasterCard, American Express, Discover, JCB, Diners Club*Also Supported = PayPal             
  • CIM = Australia, Austria, Belgium, Canada, Czech Republic, Denmark, Finland, France, Germany, Iceland, Ireland, Italy, The Netherlands, Norway, Spain, Sweden, Switzerland, United Kingdom, United States
    Supported Card Types = Visa, MasterCard, American Express, Discover
  • PayPal Website Payments Pro = US
    Supported Card Types = Visa, MasterCard, American Express, Discover
  • NMI = Australia, Austria, Belgium, Canada, China, Czech Republic, Denmark, Finland, France, Germany, Hong Kong, Iceland, India, Indonesia, Ireland, Italy, Malaysia, The Netherlands, New Zealand, Norway, Russia, Singapore, South Africa, Spain, Sweden, Switzerland, Taiwan, Turkey, United Kingdom, United States
    Supported Card Types = Visa, MasterCard, American Express, Discover
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