Why “EE.UU.” and not “E.U.” for “Estados Unidos”?

This is a common question I get. The answer is very simple.

In Spanish, when we want a word to be “initialized” (for the sake of this explanation we are going to assume that “to initialize” means “to write the initials of a word”), we have to use double letter if the word is in plural. See the examples below:

• Estados Unidos EE. UU.
• Naciones Unidas NN. UU.
• Relaciones Públicas RR. PP.
• Recursos Humanos RR. HH.
• Servicios Higiénicos SS. HH.

That was a short and easy explanation to give.