Escribo el número de servicio y el vencimiento.

Escribo is the first-person singular present tense of escribir = to write.

So:

• escribo = I write / I am writing

Spanish often leaves out the subject pronoun, so yo escribo and escribo both mean I write. The yo is usually omitted because the verb ending already shows who is doing the action.

It can mean either one, depending on context.

In Spanish, the simple present often covers both:

• I write
• I am writing

If you specifically want to emphasize I am writing right now, Spanish can also use:

• Estoy escribiendo

But in many everyday situations, escribo is perfectly natural.

Spanish is a pro-drop language, which means subject pronouns are often omitted when the verb ending makes the subject clear.

• Escribo already tells you the subject is I
• So yo is not necessary

You could say Yo escribo el número de servicio y el vencimiento, but that usually adds emphasis, contrast, or clarity.

Literally, it means number of service, but in natural English it is usually understood as service number.

The structure noun + de + noun is very common in Spanish for expressing relationships that English often shows with a noun used like an adjective.

Examples:

• número de teléfono = telephone number
• tarjeta de crédito = credit card
• centro de salud = health center

So número de servicio is a normal Spanish way to say service number.

De servicio is used because it describes the type or purpose of the number: a service number.

Compare:

• número de servicio = service number in a general labeling sense
• número del servicio = the number of the service, referring to a specific service already known from context

So in this sentence, de servicio sounds like the standard label or category.

Spanish often repeats the definite article with each noun:

• el número
• el vencimiento

Even though English might say the service number and expiration date, Spanish commonly says the number ... and the due date/expiration with the article before both nouns.

This is very natural in Spanish, especially when two separate things are being listed.

Vencimiento usually refers to a due date, expiration date, or date of expiration/maturity, depending on context.

Common possibilities:

• on a bill or payment: due date
• on a card or document: expiration date
• in finance: maturity date

So the exact English translation depends on what kind of information is being written down.

Because the noun itself is masculine: el vencimiento.

In Spanish, noun gender is grammatical, and it does not always match any logical rule from English. Here you simply learn it as:

• el vencimiento

Since it is masculine singular, the article is el.

Número has a written accent because the stress falls on the first syllable: NÚ-me-ro.

It is an esdrújula word, meaning the stress is on the third-to-last syllable. In Spanish, all esdrújulas take a written accent.

So:

• número
• not numero

Yes. Y is the normal Spanish word for and.

It only changes to e before words that begin with an i sound:

• padre e hijo
• España e Italia

But here the next word is el, so y is correct:

• el número de servicio y el vencimiento

Yes. It is the direct object of escribo.

The verb escribir here means to write down something, and the things being written are:

• el número de servicio
• el vencimiento

So the structure is:

• Escribo = verb
• el número de servicio y el vencimiento = what is being written

Yes, depending on context.

• Escribo = I write
• Anoto = I write down / note down

If the idea is specifically writing the information down for record-keeping, anoto may sound even more precise. But escribo is still correct and natural.