The duty is yours, not the software's
Whoever publishes the listing carries the disclosure obligation. Not the editing tool, not the photographer who made the alteration, and not the MLS. That is worth stating plainly because most tools in this category are sold as though buying them discharges something. They do not. What a tool can do is make the obligation cheap to meet.
What a rule actually asks for
The common mistake is reading these rules as a labelling requirement. Several of them are not. §10140.8 asks for a conspicuous statement and a link to a page showing the original. Canopy MLS asks for the unaltered image to sit immediately before or after the edited one in the photo sequence. SDMLS says labelling alone is not sufficient and asks for the original to be uploaded adjacent to the altered image.
Three different rules, one shared demand: produce the original. A label on its own satisfies none of them.
Where we say we do not know
We have not read the rules of most other MLSs. Some are behind a member login and some we have not reviewed yet, so we say nothing about what they require rather than fill it in from a competitor's blog post. If you belong to one, your MLS's own rulebook is the answer. Several tools in this category publish per-offence fines for Canopy that appear nowhere in what Canopy publishes. SDMLS does publish a fine basis: its schedule lists a $500 maximum for rule 11.5, whose heading in its July 2026 rules cross-references the altered-image rules, doubled for a second offence within a year. Being the accurate one is the entire point of this product.