With Big River, you can accept multiple types of payment for a transaction.  For your internally-used forms, Cash and Check payments can be added.  This allows you to track in reports which transactions were paid with cash or check in addition to credit card, making reconciliation with your financial team easy.  

From your Page editor, open the Contents tab, select Payment Options and Create.  The Payment Options edit popup allows you to select Cash Payment Option and Check Payment Option:

These payment options will appear on your form alongside any credit card or electronic check options you've added to the form.  

For Check payments you can capture the check number for reporting and reconciliation.  You can set the text to be used as the prompt on the form and the confirmation page and receipt by editing the payment option.

When a Cash or Check payment option is selected, the Payment Processed date is automatically set to the current date and time, signifying that the payment has been received.  Because of this, you should only use these options for forms that only your internal staff or volunteers that handle cash or checks will have access to.  If you want to present constituents using your publicly available online forms to pay later, use the Bill Me Payment Option, which is similar to the Check Payment Option, but does not mark the payment as having been processed.

Cash and Check payments will be marked as such on transaction reports.