For payments that were received outside of iNet, please follow the steps below on how to record these in iNet
Navigate to the invoice that you are working on. Once you are there, click "More" and then "Payments"
You will be show all the payments for this invoice. Please click "Create New"
Please enter the amount you received and you can specify the method of payment it was (in this case it was a check)
Once the amount and payment method has been inputted, please click "Save". This will record the payment within iNet so it shows up in analytics and in the customer record.