El formulario de cargos no reconocidos aparece.

The subject is El formulario de cargos no reconocidos.

So the sentence is structured like this:

• El formulario de cargos no reconocidos = the form for unrecognised charges
• aparece = appears / comes up / is displayed

In other words, the whole noun phrase is the thing that appears.

Because formulario is a masculine singular noun in Spanish, so it takes el.

• el formulario = the form

If the noun were feminine, you would use la instead.

In Spanish, de + noun is very often used to describe what kind of thing something is.

So:

• formulario de cargos no reconocidos = form of / for unrecognised charges

This is very natural in Spanish. English often uses for, while Spanish often uses de in these noun combinations.

Similar examples:

• tarjeta de crédito = credit card
• formulario de inscripción = registration form
• centro de salud = health centre

Yes, cargo can mean position, post, or responsibility in other contexts.

But here it is being used in a financial sense:

• cargo = a charge, debit, or amount posted to an account/card

So cargos no reconocidos refers to charges or transactions that the person does not recognise.

This is a good example of how Spanish words can have different meanings depending on context.

Because the phrase is talking about unrecognised charges in general, not just one single charge.

• cargo no reconocido = unrecognised charge
• cargos no reconocidos = unrecognised charges

Even if the form could sometimes be used for one charge, Spanish often names this kind of form with the plural because it refers to the category of issue.

Because reconocidos agrees with cargos, not with formulario.

Here is the agreement:

• cargos = masculine plural
• therefore reconocidos = masculine plural

So:

• cargo no reconocido
• cargos no reconocidos

This is a very common point for learners: the adjective belongs to the noun right next to it, not necessarily to the first noun in the sentence.

Because no reconocidos means not recognised.

Here, no is negating the adjective/past participle reconocidos.

So:

• cargos reconocidos = recognised charges
• cargos no reconocidos = unrecognised / not recognised charges

This placement is normal in Spanish.

It is originally the past participle of reconocer (to recognise), but here it is being used as an adjective.

This is very common in Spanish.

For example:

• una puerta cerrada = a closed door
• documentos perdidos = lost documents
• cargos no reconocidos = unrecognised charges

So although it comes from a verb, in this sentence it functions like an adjective describing cargos.

Because the subject is singular: El formulario.

Even though cargos is plural, that is inside a de-phrase describing the form. It is not the main subject.

So the agreement is:

• El formulario ... aparece
• not aparecen

This is similar to English: The form for unrecognised charges appears. The main noun is form, not charges.

Aparece is the third person singular present indicative of aparecer.

• yo aparezco
• tú apareces
• él/ella/usted aparece

In interface text or instructions, the present tense is very common because it describes what happens on the screen:

• La página aparece
• El menú aparece
• El formulario aparece

It can mean both, depending on context.

In everyday Spanish, especially in digital or interface contexts, aparece often means:

• appears
• comes up
• shows up
• sometimes effectively is displayed

So if this sentence is talking about something on a screen, aparece is very natural.

Yes. That would also be possible, but the nuance is slightly different.

• aparece = appears / comes up
• se muestra = is shown / is displayed
• se abre = opens

So:

• El formulario de cargos no reconocidos aparece sounds like it comes up on the screen.
• El formulario de cargos no reconocidos se muestra sounds a bit more formal or technical.

Because in Spanish, after de, the article is often omitted when you are naming a type or category of thing.

So:

• formulario de reclamación
• tarjeta de crédito
• formulario de cargos no reconocidos

This is normal.

If you were referring to a very specific set of charges, you might include an article:

• el formulario de los cargos no reconocidos de abril

But in the original sentence, it is just naming the type of form.

Yes, both are possible.

• El formulario de cargos no reconocidos aparece puts the focus first on the form itself.
• Aparece el formulario de cargos no reconocidos sounds a bit more like the form appears as an event.

Spanish often allows more flexibility in word order than English. Both versions are grammatical; the difference is mainly one of emphasis and style.