What you have to register, and with whom
Updated
An unusually branching answer, because the three categories register with three different regimes.
It depends on the category
Which is why the determination comes before this page rather than after it.
Registration follows the category, and a maker who assumes the lightest one and markets like the middle one has registered for the wrong thing.
Exempt soap
No FDA cosmetic facility registration and no product listing, because exempt soap is outside FDA's cosmetic authority.
It falls to the Consumer Product Safety Commission instead, which does not operate a registration scheme of that kind but does carry the product-safety obligations.
So on the federal side this is the light path, and the whole question becomes whether the exemption actually holds.
A cosmetic
MoCRA introduced facility registration and product listing obligations for cosmetic products.
There are small business exemptions, and they are defined by thresholds rather than by feeling small, so they have to be read against your own figures.
Safety substantiation and adverse event record obligations sit alongside them.
Which is the path most handmade soap is actually on, because of the claims it is sold with.
A drug, and the state layer
A drug brings drug establishment registration and drug listing, plus the monograph or application route, which is a different order of undertaking.
Separately from all three, the state and local layer applies: business registration, sales tax, any state cosmetic manufacturer registration, zoning and home occupation rules.
That layer applies even to exempt soap, which is the point makers most often miss.