How to Say "first letter" in Spanish
The Spanish word for “first letter” is “inicial” — A2 level. This is a very common word in everyday Spanish.
English → SpanishA2
nounA2
letter in a word

Examples
Solo necesito que escribas tu inicial en este documento.
I just need you to write your initial on this document.
Mis iniciales son L. R. C.
My initials are L. R. C.
Always Feminine
When 'inicial' refers to a letter, it is always a feminine noun: 'la inicial' (the initial) or 'las iniciales' (the initials).
Learn Spanish with Inklingo
Interactive stories, personalized learning, and more.