We anticipate you have criteria for those who have been affected by the pandemic and need assistance. For those customers, I would not advise charging a fee. Whether formalized or not, you probably have a team of individuals in your institution, which I’m guessing you are likley a part of, that is working on determine what kind of assistance to offer and how to determine to whom the assistance is extended. There should be a process for qualifying and documentation who qualifies. Perhaps this is as simple as a questionnaire. For those not negatively affected by the pandemic, I do not see an issue with charging your normal fee.
The regulators are encouraging banks to communicate with them. That might be something you want to do as you work through the details of your assistance program so there are no surprises at the next exam.