If your surname is EZARD, the most common spelling mistake is EZZARD. It is probably because of this mistake, and possible confusion with the names ISARD/ISSARD/IZARD/IZZARD, that EZZARD established itself as a separate name.
In my own experience, even people who are supposed to know how to spell the name sometimes make mistakes. Take a look at this inscription in a book I was given when I was very young. The kind lady who gave me the book had known my family for over half a century, yet this is what she wrote:
You can see my childish scribbles(!) but by the time I could write properly I copied some of the words (‘For Jill’) and corrected my surname to what it should be. Yes, I know, very pernickety…
At the end of the American Civil War, 1861-1865, a similar confusion with the EZARD surname was made by the clerk who wrote the reference envelope for the military record of Joseph F Ezard:
Ezard, Joseph F
Co A (36 Broyles’) Georgia Infantry (Confederate)
Private / Sergeant
Reference envelope: Ezzard, Joseph F
Ref: US National Archives Catalog ID 586957/Record Group 109/Roll 425
Those two forms of the name appear within about an inch of each other, written in the same hand. The clerk simply did not pay attention to what he was writing. And even now, 150 years after that mistake was made, the clerical error still causes lots of confusion when you search for Joseph F Ezard.