When getting the list of Payment Methods from the REST v2 API (https://api.infusionsoft.com/crm/rest/v2/paymentMethods), we are unable to filter by the credit_card_id field.
Filtering by payment_method_id works (filter=payment_method_id%3D%3D1234).
Filtering by contact_id works (filter=contact_id%3D%3D1234).
Filtering by merchant_account_id works (filter=merchant_account_id%3D%3D1234).
Filtering by credit_card_id returns a full list of Payment Methods, regardless of what the credit_card_id is (filter=credit_card_id%3D%3D1234).
Running multiple filters at once also works for all other id filters except credit_card_id (filter=credit_card_id%3D%3D1234%3Bcontact_id%3D%3D1234).
Filtering by any other value not listed in the API doc correctly throws an error (filter=payment_method_type%3D%3DCARD, error message is “Field filter does not have a matching enum for value payment_method_type. Valid values are: PAYMENT_METHOD_ID, CREDIT_CARD_ID, CONTACT_ID, MERCHANT_ACCOUNT_ID, SINCE_TIME, UNTIL_TIME.”)
So there is a proper enum for CREDIT_CARD_ID, at least. But the filter applied to it is missing.