Sin cita previa, no aceptan la solicitud; además, el requisito principal es llevar el pasaporte.

In Spanish, articles are often omitted in set expressions like sin cita previa, especially when talking about something in a general, non-specific way.

• sin cita previa = without a prior appointment / without an appointment
• sin una cita previa is grammatically possible, but it sounds less natural here.

In Spain, cita previa is a very common fixed expression in official contexts.

Cita means appointment, and previa means prior or previous. Together, cita previa means an appointment made in advance.

This is especially common in Spain for government offices, medical visits, paperwork, and similar situations.

Aceptan is third person plural: they accept. In Spanish, this form is often used in an impersonal way when the speaker does not say exactly who they are.

So:

• No aceptan la solicitud = They do not accept the application / The application is not accepted

It often sounds more natural in Spanish than naming the institution directly.

Spanish usually omits subject pronouns when they are not needed, because the verb ending already shows the person.

• aceptan already tells us it is they
• So ellos aceptan is usually unnecessary unless you want emphasis or contrast

This is very normal in Spanish.

Spanish often uses the definite article more than English does.

Here, la solicitud refers to the application/request in a general but identifiable official sense. In administrative Spanish, this is very common.

Compare:

• No aceptan la solicitud = They do not accept the application
• No aceptan solicitudes = They do not accept applications

The original sentence refers to the application as a type of official document.

Además means besides, furthermore, or in addition. It adds another piece of information.

So the sentence structure is:

• first idea: Sin cita previa, no aceptan la solicitud
• second idea: además, el requisito principal es llevar el pasaporte

It works like also or moreover, but in a slightly more formal way.

The semicolon links two closely related complete ideas. It is stronger than a comma but weaker than a full stop.

Here it separates:

1. Without an appointment, they do not accept the application
2. In addition, the main requirement is to bring your passport

A full stop would also be possible, but the semicolon shows the ideas are closely connected.

In Spanish, an infinitive can act like a noun phrase.

So:

• El requisito principal es llevar el pasaporte
• literally: The main requirement is bringing/to bring the passport

Here llevar el pasaporte functions as the thing that the requirement consists of.

This structure is very common:

• Lo importante es estudiar
• La idea es salir temprano
• El problema es esperar tanto

Both verbs can sometimes be translated as to bring, but they are used differently.

• llevar = to carry / take / bring with you
• traer = to bring toward the place or speaker

In many practical instructions, Spanish often uses llevar to mean have it with you / bring it along.

So llevar el pasaporte here means to bring your passport with you.

Spanish often uses the definite article where English uses a possessive, especially when the context makes possession obvious.

Here, in an official requirement, el pasaporte naturally means your passport.

Compare:

• Lleva el pasaporte = Bring your passport
• Lleva tu pasaporte = Bring your passport

Both are possible, but el pasaporte sounds very natural and less emphatic.

Not exactly.

• solicitud is the usual word for an official application or request
• petición is more like a request or petition
• aplicación usually means app, application of something, or putting something into practice, not an application form in most contexts

So in paperwork or bureaucracy, solicitud is the correct and natural choice.

Yes. A very common alternative would be:

• Sin cita previa, no se acepta la solicitud.

This is another impersonal/passive-style way to express the same idea:

• No aceptan la solicitud = They do not accept the application
• No se acepta la solicitud = The application is not accepted

Both are natural. The version with aceptan sounds a bit more like an unnamed they, while se acepta sounds more institutional or formal.