The correct singular possessive form is Perez's.
However, some people treat a singular noun ending in 'z' as they would a singular noun ending in 's'. There are two accepted possessive forms for singular nouns ending in 's':
Add an apostrophe (') after the existing s at the end of the word: Paris'
Add an apostrophe s ('s) after the existing s at the end of the word: Paris's
So, if you wish, you may use the possessive form Perez'.
Ms. Perez' cat
The plural of the name Perez is the Perezes.
Both forms, Perez' permission and Perez's permission, are correct. The choice between them depends on the style guide you follow or personal preference. Just be consistent in your usage throughout the letter.
Tyron Perez's birth name is Jojo Perez.
Davy Perez's birth name is David Perez.
Milly Perez's birth name is Milagros I. Perez.
Timo Perez's birth name is Timoniel Perez.
Chris Perez
no
No !
Adrieanne Perez's birth name is Adrieanne Perez Rivera.
Clara Perez's birth name is Clara Perez-Adamson.
Juliana Perez's birth name is Juliana Perez Caro.