Learn about the difference between online and offline payments/refunds and when to use each.
Offline Payments/Refunds
Offline payments and refunds are used for recording purposes only and are not actually sent through any payment processor. The time when you would utilize offline payments/refunds is if you are taking payments outside of Firefly but still want to record them in Firefly for tracking purposes. You will be given the option to record a payment as offline when making a new payment.
New payment popup
If you want to collect/record a payment as offline you would simply check Collect payment offline. As you can see, there is a warning given in red that will remind you offline payments are NOT processed through Firefly. Then hit Save.
Recorded offline payment
The charge will then update to being paid, however as you can see in the () after Credit/Debit Card it says "offline". Again this means that no real money was actually processed through Firefly.
You can also record offline refunds on offline payments. Click 
next to the offline payment and click refund. Since the payment was made offline, you will only be able to process the refund offline since no real payment is associated with it.
What if I accidently process a payment offline?
More than likely, you will be processing payments through Firefly and will always want to be taking ONLINE payments using the payment method a guest has on file (if using Credit/debit or ACH). Good news, if you accidently select Collect Payment Offline instead of Use Card on File and hit save you can easily reverse the offline payment and redo it correctly using the card on file
First find the payment that was taken offline and click 
next to the payment. You will then see a dropdown. Any offline payment is able to be deleted since it's just a recording, thus simply just hit Delete. This will not affect any reporting in the future.
Select Delete to remove the offline payment
This will then remove the offline payment and reset the charge for a payment to be added again. Now to correctly add an online payment, add a new payment and select Use Card on File. Read here for more instruction on payments
What if I accidently process a refund offline?
Sometimes a user will take payment correctly but then accidently process a refund offline. Just like payments, this means that no money was actually returned the the customers card, the refund was just recorded.
For example, take the picture below. A payment was taken ONLINE to a guests Credit Card for $280. However, when the refund was being done, the issuer accidently selected "Process Refund Offline", thus issuing it as an OFFLINE refund.
Example of offline refund
However, good news, as mentioned above any offline payment/refund can easily be deleted without affecting anything else since its just a recording. Simply just hit next to the refund and select Delete. Once deleted you can go back and process the refund correctly back "To the Credit/Debit Card used to pay".