Recarregue o plano pré-pago; caso contrário, perde o pacote de dados.

Because this is an imperative form, meaning a command or instruction: Top up / Recharge.

In Brazilian Portuguese, the imperative for você often uses the same form as the present subjunctive. So:

• você recarrega = you recharge
• recarregue! = recharge! / top up!

This sentence is speaking directly to the reader in the você form, which is very common in Brazil, especially in instructions, warnings, and customer messages.

If the sentence were using tu, you would more likely see recarrega.

It is not extremely formal, but it is more neutral and standard than a very casual spoken command.

In Brazilian Portuguese, using the você imperative like recarregue is common in:

• advertisements
• app notifications
• customer service messages
• written instructions

So it sounds natural for a phone company or app message. It is polite-neutral rather than intimate.

Here, recarregar means to add credit or renew/top up a prepaid mobile service.

Depending on context, English might translate it as:

• top up the prepaid plan
• recharge the prepaid plan
• add credit to the prepaid plan

In Brazil, people also often say:

• recarregar os créditos
• fazer uma recarga
• recarregar o celular pré-pago

So recarregar o plano pré-pago is understandable and natural in a telecom context, even though other similar phrases are also common.

Because pré-pago is a compound adjective meaning prepaid.

In standard Portuguese spelling, many compounds with prefixes such as pré- keep the hyphen, especially when pré keeps its stress and clear independent sound.

So:

• pré-pago = prepaid
• pré-natal = prenatal
• pré-história = prehistory

That is why you see plano pré-pago.

Portuguese uses definite articles more often than English does.

So where English might say:

• Top up your prepaid plan or you lose data

Portuguese often prefers:

• Recarregue o plano pré-pago
• perde o pacote de dados

The articles o and o sound natural because the plan and the data package are specific and understood from the situation.

In English, leaving out the often sounds fine. In Portuguese, using the article is very normal.

Caso contrário means otherwise or if not.

It is a fixed expression used to introduce the negative consequence of not doing something.

So:

• Recarregue o plano pré-pago; caso contrário, perde o pacote de dados.
• Top up the prepaid plan; otherwise, you lose the data package.

It is a bit more formal or written than senão, which can also mean otherwise in many contexts.

Yes. A common alternative is senão.

For example:

• Recarregue o plano pré-pago, senão perde o pacote de dados.

This is a little more conversational.
Caso contrário sounds slightly more formal, official, or written, which fits warning messages well.

Portuguese often uses the present tense to express a likely future result, especially in warnings, instructions, and conditions.

So:

• perde = literally loses
• but in context it means will lose

This is very natural in Portuguese.

Compare:

• Não paga, perde o acesso.
• If you don’t pay, you lose / will lose access.

A more explicit future form would be:

• caso contrário, perderá o pacote de dados
• caso contrário, vai perder o pacote de dados

Those are also possible, but perde is shorter and very common in this kind of message.

The subject is an implied você.

Portuguese often leaves out the subject pronoun when it is clear from context. Here, the sentence is clearly addressing the reader directly:

• Recarregue... = command to you
• therefore perde... = you lose / you will lose

So the full idea is:

• caso contrário, você perde o pacote de dados

But leaving out você is very normal.

Because você uses third-person verb forms in Portuguese.

So:

• você perde
• ele perde
• ela perde

They all use perde.

This is one of the first things English speakers usually need to get used to: você means you, but the verb behaves like he/she in form.

Pacote de dados means data package, data bundle, or data allowance, depending on the context.

In mobile phone service, it refers to the amount of internet/mobile data included in the plan or recharge.

So if you do not top up in time, the message says you lose that data package or data benefit.

Yes, it is natural, especially for a telecom warning, SMS, or app notification.

That said, in real Brazilian usage, you might also see variations such as:

• Recarregue seu pré-pago; caso contrário, você perde o pacote de dados.
• Faça uma recarga; caso contrário, perde o pacote de internet.
• Recarregue os créditos; senão perde o pacote de dados.

So the original sentence is perfectly understandable and natural, but there are several other common ways to say the same kind of thing.