In Mexico, consumers do not ask permission before reshaping a foreign brand name. "Little Caesars" became "Liru Sisa" in everyday speech, and the phonetic version spread faster than the original.
The company response was the interesting part. Rather than treating the nickname as a distortion to be corrected, it filed "Liru Sisa" as a trademark before IMPI. In one filing it captured the goodwill the public had generated for free and closed the door on anyone else registering it.
Why this is good trademark strategy
Trademark rights in Mexico are acquired by registration, not by use. If a third party had filed "Liru Sisa" first, that party would hold the registration, and Little Caesars would have been left arguing bad faith or notoriety after the fact, which is slower, costlier and far from certain.
The same reasoning applies at any scale. If your customers consistently call your business something other than the name on your sign, that nickname is already an asset. It appears in search queries, in word of mouth and in social posts, and it is registrable if it is distinctive.
What to do about it
Audit the names your market actually uses, not just the one on your incorporation documents. Then file the ones with commercial traction in the Nice classes where you trade. A defensive filing is inexpensive compared with recovering a name someone else registered.
How Mexican law treats the nickname
Confusing similarity is assessed phonetically, not only visually. A later application that sounds like your mark can be refused under article 173 of the Mexican Industrial Property Law, which is the same reason your own phonetic variant is worth owning rather than tolerating.
Two practical consequences. First, if the nickname is already how customers ask for you, filing it is not vanity, it is closing the door through which a competitor would otherwise walk. Second, each variant is a separate application in each class you need, so the decision is a budget one: pick the variants that actually circulate, not every spelling you can imagine.
And remember the obligation that follows. Three years after each registration is granted you must declare real and effective use, and protection continues only for the goods or services actually declared (article 233). A defensive filing you never use is a filing you will lose, so register the variants you will genuinely put on packaging, menus or advertising.