Нужно уведомить страховщика сегодня.

Нужно means it is necessary / one must / need to. In Russian, this word is often used in impersonal sentences, where there is no stated subject like I, you, or we.

So Нужно уведомить страховщика сегодня literally works like:

It is necessary to notify the insurer today.

Russian very often leaves the person unspecified when the context already makes it clear, or when the statement is meant more generally.

Уведомить is the perfective infinitive, while уведомлять is the imperfective infinitive.

Here, уведомить is used because the sentence refers to a single completed action: the insurer needs to be notified. The focus is on getting that action done.

• нужно уведомить = it is necessary to notify (and complete that act)
• нужно уведомлять would suggest a repeated process, a general practice, or ongoing notifying, which does not fit this sentence well

Because сегодня points to a specific occasion, the perfective verb is the natural choice.

Страховщика is the accusative singular form of страховщик.

The verb уведомить takes a direct object: you notify someone. In Russian, masculine animate nouns usually have:

• nominative singular: страховщик
• accusative singular: страховщика

Since an insurer is an animate noun, the accusative form matches the genitive form here.

So:

• страховщик = insurer (dictionary form)
• уведомить страховщика = to notify the insurer

Страховщик most often means the insurer — the party providing the insurance.

Depending on context, that can refer to:

• an insurance company
• an insurer in a legal/formal sense

It is usually more formal than everyday conversational wording. In some contexts, Russians might also say things like:

• страховая компания = insurance company
• страховая = insurance company, in shorter everyday speech

So страховщика here is a fairly formal and precise choice.

Russian often leaves the subject unstated when it is:

• obvious from context
• not important
• meant in a general sense

So Нужно уведомить страховщика сегодня can mean:

• You need to notify the insurer today
• We need to notify the insurer today
• It is necessary to notify the insurer today

The sentence itself does not specify who must do it. Context tells you that.

If you want to make the person explicit, Russian can do that too, for example:

• Мне нужно уведомить страховщика сегодня = I need to notify the insurer today
• Нам нужно уведомить страховщика сегодня = We need to notify the insurer today

Yes, сегодня can move around. Russian word order is fairly flexible, and moving words often changes emphasis rather than core meaning.

The neutral version here is:

• Нужно уведомить страховщика сегодня.

Other possible orders:

• Сегодня нужно уведомить страховщика.
  Emphasis on today
• Страховщика нужно уведомить сегодня.
  Emphasis on the insurer
• Нужно сегодня уведомить страховщика.
  Also possible, with slightly different rhythm

All of these can be correct. The original sentence sounds natural and neutral.

Yes, уведомить is somewhat formal. It is common in official, legal, business, and administrative contexts.

In everyday speech, people might often use:

• сообщить = to inform / tell
• сказать = to tell
• предупредить = to warn / notify in advance

For example:

• Нужно сегодня сообщить страховой компании.
  = We need to inform the insurance company today.

But in legal or policy-related situations, уведомить страховщика is very natural and appropriate.

Yes. Both are good translations, depending on style.

The Russian sentence is impersonal, so English can render it in different ways:

• It is necessary to notify the insurer today.
• The insurer must be notified today.
• You need to notify the insurer today.
• We need to notify the insurer today.

The Russian does not force one single English version. The best translation depends on context and tone.

In many cases, нужно and надо are very close and both can mean need to / have to / it is necessary.

So you could also say:

• Надо уведомить страховщика сегодня.

Broadly speaking:

• надо is often a bit more conversational and common in everyday speech
• нужно can sound slightly more neutral or formal

But in many situations, the difference is small, and both are natural.

Yes. That is very common.

You can have:

• Нужно уведомить страховщика сегодня.
  = It is necessary to notify the insurer today.
• Мне нужно уведомить страховщика сегодня.
  = I need to notify the insurer today.
• Нам нужно уведомить страховщика сегодня.
  = We need to notify the insurer today.

So нужно can appear in a fully impersonal sentence, or with a person in the dative case to show who has the obligation or need.

It sounds completely natural in both, but the combination уведомить страховщика is especially common in formal written Russian, such as:

• insurance documents
• legal instructions
• official correspondence
• policy conditions

In casual speech, many speakers might choose simpler wording, but this sentence is still perfectly correct and natural, especially if the topic is insurance or paperwork.