Check (ACH)

Overview

This page contains all API documentation for Check (ACH), and ACH-Q transactions. For more information regarding account access, navigate to the Transaction API parent page.

How to Generate Cardknox Keys

Sign in to the Cardknox Merchant Portal.
Select "Account Settings" from the navigation bar.
Select "Keys" from the sub-menu.
Click "Create a Key" in the top-right corner.
Choose the desired key type (API or iFields), description (software, etc.), and permissions.
Click "Create and View" and copy your key.

It is critical to copy your key and save it in a secure location, as you won’t be able to obtain the key again.

Endpoints

Health Check

HTTP Request Method: GET

https://x1.cardknox.com/status

Transactions

HTTP Request Method: POST

Cardknox allows you to send the data in FormData, JSON, and XML formats.

Add to the base URL any of the following formats to indicate which format you are sending it as:

FormData

/gatewayform

https://x1.cardknox.com/gatewayform

JSON

/gatewayjson

https://x1.cardknox.com/gatewayjson

XML

/gatewayxml

https://x1.cardknox.com/gatewayxml

Transactions

Cardknox provides ACH and ACHQ processing for the transactions listed below (with exception of VoidRefund, which there is only ACHQ processing for). For more information regarding ACHQ, refer to the ACHQ Developer Page or contact Cardknox support.

Sale

POST check:sale

xCommand = check:Sale The Check Sale command debits funds from a customer’s checking or savings account using one of the following options:

The merchant must have a supported Check/ACH processing account to use either of these options.

Request Body

Name Type Description

Name	Type	Description
xKey*	String	Your Cardknox API key.
xVersion*	String	Gateway API version. The current version is 5.0.0
xSoftwareName*	String	Name of your software
xSoftwareVersion*	String	Version number of your software
xCommand*	String	Cardknox transaction type
xAmount*	String	The total amount of the transaction, inclusive of tax and tip if applicable.
xToken	String	The Cardknox token that references a previously used payment method. When using a token, `xCardNum` `xExp` and `xMagstripe` should not be used.
xCustom01	String	20 custom fields are available for custom data, such as customer comments, etc. Use `xCustom01` through `xCustom20.`
xRouting*	String	The check ABA routing number
xAccount*	String	The check account number
xName*	String	Name on account
xTax	String	The tax portion that is included in the total transaction amount (xAmount)
xTip	String	The tip portion that is included in the total transaction amount (xAmount)
xInvoice	String	The merchant’s invoice number for the transaction. `xInvoice` is recommended when available for improved duplicate handling.
xPONum	String	The merchant’s purchase order number for the transaction
xComments	String	Additional data optionally passed along to the receipt
xDescription	String	Additional data optionally passed along for reporting
xIP	String	The customer’s IP address. Typically used for fraud detection
xEmail	String	The customer’s email address
xFax	String	The customer’s fax number
xBillFirstName	String	The customer’s first name for their billing profile
xBillMiddleName	String	The customer’s middle name or initial for their billing profile
xBillLastName	String	The customer’s last/family name for their billing profile
xBillCompany	String	The customer’s company name for their billing profile
xBillStreet	String	The customer’s street address for their billing profile
xBillStreet2	String	The customer’s street address 2nd line for their billing profile
xBillCity	String	The customer’s city for their billing profile
xBillState	String	The customer’s state for their billing profile
xBillZip	String	The customer’s zip code for their billing profile
xBillCountry	String	The customer’s country for their billing profile
xBillPhone	String	The customer’s phone number for their billing profile
xShipFirstName	String	The customer’s first name for their shipping profile
xShipMiddleName	String	The customer’s middle name or initial for their shipping profile
xShipLastName	String	The customer’s last/family name for their shipping profile
xShipCompany	String	The customer’s company name for their shipping profile
xShipStreet	String	The customer’s street address for their shipping profile
xShipStreet2	String	The customer’s street address 2nd line for their shipping profile
xShipCity	String	The customer’s city for their shipping profile
xShipState	String	The customer’s state for their shipping profile
xShipZip	String	The customer’s zip code for their shipping profile
xShipCountry	String	The customer’s country for their shipping profile
xShipPhone	String	The customer’s phone number for their shipping profile
xShipMobile	String	The customer’s mobile number for their shipping profile
xMICR	String	The routing, account and check number data from the bottom of a check in MICR (Magnetic Ink Character Recognition) format, typically generated by a check scanner
xCheckNum	String	The check number
xCheckImageFront	String	The front image of the check, in Base 64 encoded image format.
xCheckImageRear	String	The back image of the check, in Base 64 encoded image format.
xOrderID	String	Unique order number for FraudWatch verification
xExistingCustomer	String	Yes/No value indicating if the customer is a repeat customer
xAllowDuplicate	String	By default, Cardknox rejects duplicate transactions within 10 minutes of the original transaction. This command overrides that safeguard. True/False allowed.
xCustReceipt	String	True/False value indicating if the email address specified in `xemail` should receive a receipt containing the transaction details
xCurrency	String	Used to specify an alternate currency. Only applicable for accounts that are using Multi-Currency Conversion (MCC). For accounts that are natively in a foreign currency, the currency does not need to be specified. (see list of all supported currencies).
xBillMobile	String	The customer’s mobile number for their billing profile
xAccountType	String	Type of account: Checking or Savings
xTimeoutSeconds	String	Configurable amount of seconds in which the request will wait for a response.
xSupports64BitRefnum	String	True/False value indicating that the user’s system can handle a 64bit refnum getting returned on request to the transaction.

xKey*

String

Your Cardknox API key.

xVersion*

String

Gateway API version. The current version is 5.0.0

xSoftwareName*

String

Name of your software

xSoftwareVersion*

String

Version number of your software

xCommand*

String

Cardknox transaction type

xAmount*

String

The total amount of the transaction, inclusive of tax and tip if applicable.

xToken

String

The Cardknox token that references a previously used payment method. When using a token, xCardNum xExp and xMagstripe should not be used.

xCustom01

String

20 custom fields are available for custom data, such as customer comments, etc. Use xCustom01 through xCustom20.

xRouting*

String

The check ABA routing number

xAccount*

String

The check account number

xName*

String

Name on account

xTax

String

The tax portion that is included in the total transaction amount (xAmount)

xTip

String

The tip portion that is included in the total transaction amount (xAmount)

xInvoice

String

The merchant’s invoice number for the transaction. xInvoice is recommended when available for improved duplicate handling.

xPONum

String

The merchant’s purchase order number for the transaction

xComments

String

Additional data optionally passed along to the receipt

xDescription

String

Additional data optionally passed along for reporting

xIP

String

The customer’s IP address. Typically used for fraud detection

xEmail

String

The customer’s email address

xFax

String

The customer’s fax number

xBillFirstName

String

The customer’s first name for their billing profile

xBillMiddleName

String

The customer’s middle name or initial for their billing profile

xBillLastName

String

The customer’s last/family name for their billing profile

xBillCompany

String

The customer’s company name for their billing profile

xBillStreet

String

The customer’s street address for their billing profile

xBillStreet2

String

The customer’s street address 2nd line for their billing profile

xBillCity

String

The customer’s city for their billing profile

xBillState

String

The customer’s state for their billing profile

xBillZip

String

The customer’s zip code for their billing profile

xBillCountry

String

The customer’s country for their billing profile

xBillPhone

String

The customer’s phone number for their billing profile

xShipFirstName

String

The customer’s first name for their shipping profile

xShipMiddleName

String

The customer’s middle name or initial for their shipping profile

xShipLastName

String

The customer’s last/family name for their shipping profile

xShipCompany

String

The customer’s company name for their shipping profile

xShipStreet

String

The customer’s street address for their shipping profile

xShipStreet2

String

The customer’s street address 2nd line for their shipping profile

xShipCity

String

The customer’s city for their shipping profile

xShipState

String

The customer’s state for their shipping profile

xShipZip

String

The customer’s zip code for their shipping profile

xShipCountry

String

The customer’s country for their shipping profile

xShipPhone

String

The customer’s phone number for their shipping profile

xShipMobile

String

The customer’s mobile number for their shipping profile

xMICR

String

The routing, account and check number data from the bottom of a check in MICR (Magnetic Ink Character Recognition) format, typically generated by a check scanner

xCheckNum

String

The check number

xCheckImageFront

String

The front image of the check, in Base 64 encoded image format.

xCheckImageRear

String

The back image of the check, in Base 64 encoded image format.

xOrderID

String

Unique order number for FraudWatch verification

xExistingCustomer

String

Yes/No value indicating if the customer is a repeat customer

xAllowDuplicate

String

By default, Cardknox rejects duplicate transactions within 10 minutes of the original transaction. This command overrides that safeguard. True/False allowed.

xCustReceipt

String

True/False value indicating if the email address specified in xemail should receive a receipt containing the transaction details

xCurrency

String

Used to specify an alternate currency. Only applicable for accounts that are using Multi-Currency Conversion (MCC). For accounts that are natively in a foreign currency, the currency does not need to be specified. (see list of all supported currencies).

xBillMobile

String

The customer’s mobile number for their billing profile

xAccountType

String

Type of account: Checking or Savings

xTimeoutSeconds

String

Configurable amount of seconds in which the request will wait for a response.

xSupports64BitRefnum

String

True/False value indicating that the user’s system can handle a 64bit refnum getting returned on request to the transaction.

Sale - Request Payload Example

{
    "xKey": "[xkeycredentials]",
    "xVersion": "4.5.9",
    "xSoftwareName": "YourSoftwareName",
    "xSoftwareVersion": "1.0.0",
    "xCommand": "check:sale",
    "xAmount": "35.00",
    "xToken": "61h72mmh68phn9q233634ph3g54p1499m69qhp4816pn528h84",
    "xCustom01": "Register01",
    "xRouting": "12345678",
    "xAccount": "123456789",
    "xAccountType": "Checking",
    "xName": "John Doe",
    "xTax": "2.00",
    "xTip": "2.00",
    "xInvoice": "123456A",
    "xPONum": "123456B",
    "xComments": "This is a comment",
    "xDescription": "This is a description",
    "xIP": "1.2.3.4",
    "xEmail": "text@example.com",
    "xFax": "1234567890",
    "xBillFirstName": "John",
    "xBillMiddleName": "Max",
    "xBillLastName": "Doe",
    "xBillCompany": "Acme", 
    "xBillStreet": "123 Any Street", 
    "xBillStreet2": "Apt 4b", 
    "xBillCity": "Anytown", 
    "xBillState": "NY", 
    "xBillZip": "12345", 
    "xBillCountry": "USA", 
    "xBillPhone": "8005551212", 
    "xBillMobile": "8005551111", 
    "xShipFirstName": "John", 
    "xShipMiddleName": "Max", 
    "xShipLastName": "Doe", 
    "xShipCompany": "Acme", 
    "xShipStreet": "123 Any Street", 
    "xShipStreet2": "Apt 4b", 
    "xShipCity": "Anytown", 
    "xShipState": "NY", 
    "xShipZip": "11111", 
    "xShipCountry": "USA", 
    "xShipPhone": "8005551212", 
    "xShipMobile": "8005551111", 
    "xMICR": "t021000021t 123456789o _2542",
    "xCheckNum": "999",
    "xCheckImageFront": "data:image/jpeg;base64,/9j/4AAQSkZJRgABAQEASABIAAD/2wBDAAYEBAQFBAYFBQYJBgUGCQsIBgYICwwKCgsKCgwQDAwMDAwMEAwODxAPDgwTExQUExMcGxsbHCAgICAgICAgICD/2wBDAQcHBw0MDRgQEBgaFREVGiAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICD/w",
    "xCheckImageRear": "data:image/jpeg;base64,/9j/4AAQSkZJRgABAQEASABIAAD/2wBDAAYEBAQFBAYFBQYJBgUGCQsIBgYICwwKCgsKCgwQDAwMDAwMEAwODxAPDgwTExQUExMcGxsbHCAgICAgICAgICD/2wBDAQcHBw0MDRgQEBgaFREVGiAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICD/w",
    "xOrderID": "12356",
    "xExistingCustomer": "TRUE",
    "xAllowDuplicate": "TRUE", 
    "xCustReceipt": "TRUE",
    "xCurrency": "USD",
    "xTimeoutSeconds": "10"
}

Save

POST check:save

xCommand = check:Save The Save command is used to send account information and request a token from Cardknox but does not submit the transaction for processing. The response returns a token that references the account information. A token at minimum references the account and routing number, but if other data is sent—such as billing address—that will be associated with the token as well.

Request Body

Name Type Description

Name	Type	Description
xCommand*	String	Cardknox transaction type
xRouting*	String	The check ABA routing number
xName*	String	The cardholder’s name
xSoftwareName*	String	Name of your software
xSoftwareVersion*	String	Version number of your software
xAccount*	String	The check account number
xVersion*	String	Gateway API version. The current version is 5.0.0
xCustom01	String	20 custom fields are available for custom data, such as customer comments, etc. Use `xCustom01` through `xCustom20.`
xKey*	String	Your Cardknox API key.
xIP	String	The customer’s IP address. Typically used for fraud detection.
xMICR	String	The routing, account, and check number data from the bottom of a check in MICR (Magnetic Ink Character Recognition) format, typically generated by a check scanner
xAllowDuplicate	String	By default, Cardknox rejects duplicate transactions within 10 minutes of the original transaction. This command overrides that safeguard. True/False allowed.
xSupports64BitRefnum	String	True/False value indicating that the user’s system can handle a 64bit refnum getting returned on request to the transaction.

xCommand*

String

Cardknox transaction type

xRouting*

String

The check ABA routing number

xName*

String

The cardholder’s name

xSoftwareName*

String

Name of your software

xSoftwareVersion*

String

Version number of your software

xAccount*

String

The check account number

xVersion*

String

Gateway API version. The current version is 5.0.0

xCustom01

String

20 custom fields are available for custom data, such as customer comments, etc. Use xCustom01 through xCustom20.

xKey*

String

Your Cardknox API key.

xIP

String

The customer’s IP address. Typically used for fraud detection.

xMICR

String

The routing, account, and check number data from the bottom of a check in MICR (Magnetic Ink Character Recognition) format, typically generated by a check scanner

xAllowDuplicate

String

By default, Cardknox rejects duplicate transactions within 10 minutes of the original transaction. This command overrides that safeguard. True/False allowed.

xSupports64BitRefnum

String

True/False value indicating that the user’s system can handle a 64bit refnum getting returned on request to the transaction.

Save - Request Payload Example

{
    "xKey": "[xkeycredentials]",
    "xVersion": "4.5.9",
    "xSoftwareName": "YourSoftwareName",
    "xSoftwareVersion": "1.0.0",
    "xCommand": "check.save",
    "xCustom01": "Register01",
    "xRouting": "12345678",
    "xAccount": "123456789",
    "xName": "John Doe",
    "xIP": "1.2.3.4",
    "xMICR": "t021000021t 123456789o _2542",
    "xAllowDuplicate": "TRUE"
}

Void

POST check:void

xCommand = check:Void The Void command voids a check transaction that is pending being sent to the bank, typically at the end of each day.

Request Body

Name Type Description

Name	Type	Description
xKey*	String	Your Cardknox API key.
xVersion*	String	Gateway API version. The current version is 5.0.0
xSoftwareName*	String	Name of your software
xSoftwareVersion*	String	Version number of your software
xCommand*	String	Cardknox transaction type
xCustom01	String	20 custom fields are available for custom data, such as customer comments, etc. Use `xCustom01` through `xCustom20.`
xRefNum*	String	Used to reference a previous transaction when processing a follow-up transaction; typically a refund, void, or capture. (Note: `xRefnum` can be a 64-bit number and should be stored as BIGINT, Long, Int64 or String).
xIP	String	The customer’s IP address. Typically used for fraud detection.
xSupports64BitRefnum	String	True/False value indicating that the user’s system can handle a 64bit refnum getting returned on request to the transaction.

xKey*

String

Your Cardknox API key.

xVersion*

String

Gateway API version. The current version is 5.0.0

xSoftwareName*

String

Name of your software

xSoftwareVersion*

String

Version number of your software

xCommand*

String

Cardknox transaction type

xCustom01

String

20 custom fields are available for custom data, such as customer comments, etc. Use xCustom01 through xCustom20.

xRefNum*

String

Used to reference a previous transaction when processing a follow-up transaction; typically a refund, void, or capture. (Note: xRefnum can be a 64-bit number and should be stored as BIGINT, Long, Int64 or String).

xIP

String

The customer’s IP address. Typically used for fraud detection.

xSupports64BitRefnum

String

True/False value indicating that the user’s system can handle a 64bit refnum getting returned on request to the transaction.

Void - Request Payload Example

{
    "xKey": "[xkeycredentials]",
    "xVersion": "4.5.9",
    "xSoftwareName": "YourSoftwareName",
    "xSoftwareVersion": "1.0.0",
    "xCommand": "check.void",
    "xCustom01": "Register01",
    "xRefNum": "81726356",
    "xIP": "1.1.1.1"
}

Refund

POST check:refund

xCommand = check:Refund The Refund command is used to refund the full amount of a previously settled check transaction, using xRefNum. Partial check refund isn’t supported.

Request Body

Name Type Description

Name	Type	Description
xKey*	String	Your Cardknox API key.
xVersion*	String	Gateway API version. The current version is 5.0.0
xSoftwareName*	String	Name of your software
xSoftwareVersion*	String	Version number of your software
xCommand*	String	Cardknox transaction type
xCustom01	String	20 custom fields are available for custom data, such as customer comments, etc. Use `xCustom01` through `xCustom20.`
xRefNum*	String	Used to reference a previous transaction when processing a follow-up transaction; typically a refund, void, or capture. (Note: `xRefnum` can be a 64-bit number and should be stored as BIGINT, Long, Int64 or String)
xIP	String	The customer’s IP address. Typically used for fraud detection.
xAmount*	String	The total amount of the transaction, inclusive of tax and tip if applicable. This the total amount of the transaction.
xAllowDuplicate	String	By default, Cardknox rejects duplicate transactions within 10 minutes of the original transaction. This command overrides that safeguard. True/False allowed.
xCustReceipt	String	True/False value indicating if the email address specified in `xemail` should receive a receipt containing the transaction details.
xTimeoutSeconds	String	Configurable amount of seconds in which the request will wait for a response.
xSupports64BitRefnum	String	True/False value indicating that the user’s system can handle a 64bit refnum getting returned on request to the transaction.

xKey*

String

Your Cardknox API key.

xVersion*

String

Gateway API version. The current version is 5.0.0

xSoftwareName*

String

Name of your software

xSoftwareVersion*

String

Version number of your software

xCommand*

String

Cardknox transaction type

xCustom01

String

20 custom fields are available for custom data, such as customer comments, etc. Use xCustom01 through xCustom20.

xRefNum*

String

xIP

String

The customer’s IP address. Typically used for fraud detection.

xAmount*

String

The total amount of the transaction, inclusive of tax and tip if applicable. This the total amount of the transaction.

xAllowDuplicate

String

By default, Cardknox rejects duplicate transactions within 10 minutes of the original transaction. This command overrides that safeguard. True/False allowed.

xCustReceipt

String

True/False value indicating if the email address specified in xemail should receive a receipt containing the transaction details.

xTimeoutSeconds

String

Configurable amount of seconds in which the request will wait for a response.

xSupports64BitRefnum

String

True/False value indicating that the user’s system can handle a 64bit refnum getting returned on request to the transaction.

Refund - Request Payload Example

{
    "xKey": "[xkeycredentials]",
    "xVersion": "4.5.9",
    "xSoftwareName": "YourSoftwareName",
    "xSoftwareVersion": "1.0.0",
    "xCommand": "check.refund",
    "xAmount": "9.99",
    "xCustom01": "Register01",
    "xRefNum": "81726356",
    "xIP": "1.1.1.1",
    "xAllowDuplicate": "TRUE",
    "xCustReceipt": "FALSE",
    "xTimeoutSeconds": "10"
}

VoidRefund

POST check:VoidRefund

xCommand = check:VoidRefund The VoidRefund within the ACHQ tooling is used void a check transaction that is pending being sent to the bank, typically at the end of each day. It also issues a refund. Partial refunds are also supported.

Request Body

Name Type Description

Name	Type	Description
xCommand*	String	Cardknox transaction type
xRouting*	String	The check ABA routing number
xName	String	The cardholder’s name. One of xName, xBillFirstName, or xBillLastName are required.
xSoftwareName*	String	Name of your software
xSoftwareVersion*	String	Version number of your software
xAccount*	String	The check account number
xVersion*	String	Gateway API version. The current version is 5.0.0
xCustom01	String	20 custom fields are available for custom data, such as customer comments, etc. Use `xCustom01` through `xCustom20.`
xKey*	String	Your Cardknox API key.
xIP	String	The customer’s IP address. Typically used for fraud detection.
xMICR	String	The routing, account, and check number data from the bottom of a check in MICR (Magnetic Ink Character Recognition) format, typically generated by a check scanner
xAllowDuplicate	String	By default, Cardknox rejects duplicate transactions within 10 minutes of the original transaction. This command overrides that safeguard. True/False allowed.
xSupports64BitRefnum	String	True/False value indicating that the user’s system can handle a 64bit refnum getting returned on request to the transaction.
xBillState*	String	Company Billing State
xBillCity*	String	Company Billing City
xBillStreet*	String	Company Street Address
xBillCompany*	String	Required if xCheckType = Business
xBillZip*	String	Company Billing Zip
xBillPhone*	String	Company Phone Number
xEmail*	String	Company Email
xCheckType*	String	Check Type (Business, Personal)

xCommand*

String

Cardknox transaction type

xRouting*

String

The check ABA routing number

xName

String

The cardholder’s name. One of xName, xBillFirstName, or xBillLastName are required.

xSoftwareName*

String

Name of your software

xSoftwareVersion*

String

Version number of your software

xAccount*

String

The check account number

xVersion*

String

Gateway API version. The current version is 5.0.0

xCustom01

String

20 custom fields are available for custom data, such as customer comments, etc. Use xCustom01 through xCustom20.

xKey*

String

Your Cardknox API key.

xIP

String

The customer’s IP address. Typically used for fraud detection.

xMICR

String

The routing, account, and check number data from the bottom of a check in MICR (Magnetic Ink Character Recognition) format, typically generated by a check scanner

xAllowDuplicate

String

By default, Cardknox rejects duplicate transactions within 10 minutes of the original transaction. This command overrides that safeguard. True/False allowed.

xSupports64BitRefnum

String

True/False value indicating that the user’s system can handle a 64bit refnum getting returned on request to the transaction.

xBillState*

String

Company Billing State

xBillCity*

String

Company Billing City

xBillStreet*

String

Company Street Address

xBillCompany*

String

Required if xCheckType = Business

xBillZip*

String

Company Billing Zip

xBillPhone*

String

Company Phone Number

xEmail*

String

Company Email

xCheckType*

String

Check Type (Business, Personal)

Check (ACH) FAQ

Q: How many days does it take to get the ACH status?

A: It typically takes 2-3 days.

Q: How can I get the ACH status?

A: There are a few ways to get the status. Via email, webhook, the Cardknox Portal, or by pulling a report using our reporting API.

Q: What verbiage comes back from the ACH Status?

A: You should get back the following status codes from Cardknox:

xStatus=16 “settled”
xStatus=14 “chargeback”
xStatus=0 “pending”

The daily emails may contain more information.

Q: Can we get back a token when using the check MICR?

A: Cardknox only returns tokens on check transactions that contain the routing and account number. In the event only check images and MICR were submitted, the token is not returned since it can’t be reused on subsequent transactions.

Last updated 15 days ago