La declaración de la renta indica el domicilio fiscal.

In Spain, la declaración de la renta usually means the income tax return.

A few useful points:

• declaración = declaration, return, statement, filing
• la renta = income, but in this context it refers to income tax
• As a full expression, la declaración de la renta is a set phrase in Spain for the annual income tax return

So even though the words literally look like the declaration of the income, the natural English meaning is the income tax return.

In Spain, la renta is treated as a specific, known concept: income tax / income for tax purposes. That is why the article la appears.

So:

• de la renta = of the income / of income tax
• de renta would sound incomplete or unnatural here in standard Spanish from Spain

This is just how the established expression works:

• hacer la declaración de la renta
• presentar la declaración de la renta

Because the subject is singular: La declaración de la renta.

The main noun is declaración, which is singular, so the verb must also be singular:

• La declaración ... indica = The tax return indicates ...
• Las declaraciones ... indican = The tax returns indicate ...

Even though the phrase is long, the verb agrees with declaración, not with renta.

Indica comes from indicar, which means:

• to indicate
• to state
• to show

In this sentence, a natural translation could be:

• The tax return shows the tax address
• The tax return states the fiscal address

So indica is slightly formal and administrative here, which fits the context.

Domicilio fiscal means tax address or fiscal address.

It is not always just any place where someone lives. In legal and tax contexts, it means the address officially registered for tax purposes.

Compare:

• domicilio = address / residence / registered address
• domicilio fiscal = tax address
• dirección = address in a more general, everyday sense

So domicilio fiscal is a formal administrative term.

Spanish often uses the definite article (el, la, los, las) where English might prefer a possessive like his, her, your, its.

So:

• indica el domicilio fiscal literally = indicates the tax address
• but in English, depending on context, we might say indicates your tax address or indicates the tax address

Spanish does not always need to specify possession if the meaning is already clear from context.

No, not exactly.

• casa = house/home
• hogar = home in the emotional or family sense
• domicilio = domicile, registered address, residence address

In official language, domicilio is much more common than casa. In tax, legal, and administrative contexts, domicilio is the normal word.

Because they belong to different noun phrases:

• La declaración = the return / the declaration
• de la renta = of the income / of income tax

So the structure is:

• La declaración
• de la renta
• indica
• el domicilio fiscal

The first la goes with declaración.
The second la goes with renta.

In Spanish, de only contracts with el:

• de + el = del
• a + el = al

But de + la does not contract.

So:

• de la renta = correct
• del renta = incorrect

That is why the sentence has de la renta, not del renta.

Indica is the third person singular present tense of indicar.

So:

• yo indico = I indicate
• tú indicas = you indicate
• él/ella/usted indica = he/she/you indicate

Here it means something like indicates or shows as a general fact.

Yes, but the given order is the most natural and neutral for this kind of statement:

• La declaración de la renta indica el domicilio fiscal.

You could sometimes change word order for emphasis, but in ordinary administrative Spanish, this standard subject-verb-object order is the clearest and most natural.

Because the stress falls on the final syllable sound -ción, and Spanish spelling rules require an accent mark there.

So it is written:

• declaración

not:

• declaracion

This pattern is very common in Spanish nouns ending in -ción:

• información
• dirección
• situación
• declaración