An Article Processing Fee is usually charged after acceptance, but you can prepay (deposit) money in advance, which is particularly useful for expiring funding (money that needs to be spent before a grant expires/ends). (Another option in this situation of an expiring grant would be to purchase an institutional membership).
JMIR Prepaid Credits act like real money. Each prepaid credit is valued at $1USD and is redeemable for anything you might want to purchase from JMIR Publications. Each credit you purchase will be valid for 365 days.
How to purchase
How to generate an invoice
If you need an invoice for Prepaid Credits, please go to the Order Checkout - Your Cart page first and select the quantity of credits you would like to purchase. Then scroll to the bottom of the Cart page and click on the Generate Invoice for Cart link.