Не позднее чем в пять часов мы вернём код доступа.

Literally, it is not later than.

• позднее = later / more late, the comparative form of поздно (late)
• не = not
• чем = than

So the structure is basically:

не позднее чем X = not later than X

This is a common and fairly formal way to give a deadline or latest possible time.

Because Russian often uses чем after a comparative, just like English uses than.

Examples:

• раньше, чем... = earlier than...
• позднее, чем... = later than...

In this sentence, the full idea is:

• не позднее, чем в пять часов = not later than at five o’clock

In natural English, we usually just say no later than five o’clock, but Russian keeps the comparative structure more visibly.

Because Russian numerals affect the noun that follows them.

With час:

• 1 час
• 2, 3, 4 часа
• 5+ часов

So:

• пять часов
• шесть часов
• десять часов

This is a very important number pattern in Russian.

Because в is commonly used for an exact clock time:

• в час = at one
• в два часа = at two
• в пять часов = at five

So в пять часов means at five o’clock.

In this sentence, that exact time point is used as the deadline. Russian often expresses this with не позднее чем + a time expression.

A related expression is к пяти часам, which means by five o’clock. That also refers to a deadline, but it is a different construction.

Вернём is the 1st person plural future form of вернуть.

So:

• вернуть = to return / give back
• вернём = we will return / we will give back

It is a perfective verb, so the simple future form means a completed action in the future.

That is why Russian can use one word, вернём, where English needs will return.

The infinitive is вернуть.

Вернём is pronounced roughly ver-NYOM. The ё shows that the stress falls there and that the sound is yo, not plain e.

In many Russian texts, ё is often written as е, so you may also see:

• вернем

But it is the same word. For learners, writing ё is very helpful because it shows the correct pronunciation.

Код is in the accusative singular, because it is the direct object of вернём.

However, since код is an inanimate masculine noun, its accusative form looks the same as the nominative:

• nominative: код
• accusative: код

Доступа is genitive singular after код.

So the phrase works like this:

• код = code
• доступа = of access

Literally: code of access

In English, we normally say access code.

Yes, very often.

Russian verb endings already show the subject:

• вернём already means we will return

So you could say:

• Не позднее чем в пять часов вернём код доступа.

That is grammatically possible.

But мы may be included:

• for clarity
• for emphasis
• to make the sentence sound slightly more explicit

Russian word order is flexible, so moving parts of the sentence changes emphasis more than basic meaning.

Starting with:

Не позднее чем в пять часов...

puts the deadline first. It highlights the time limit right away.

A more straightforward order would be:

Мы вернём код доступа не позднее чем в пять часов.

Both are correct. The version with the time first sounds a bit more focused on the deadline.

They are very close in meaning, and both can mean later.

But there is a slight style difference:

• позже = more common in everyday speech
• позднее = a bit more formal or neutral in official-style language

That is why не позднее чем sounds natural in formal instructions, notices, or business communication.

A more conversational version might use:

• не позже пяти часов

But in your sentence, не позднее чем fits the formal tone very well.

Yes, somewhat formal or official.

The main reason is the phrase:

• не позднее чем

This wording is very common in:

• announcements
• instructions
• office communication
• technical or administrative language

Also, код доступа sounds like standard technical vocabulary.

So the whole sentence sounds like something you might read in a message from a company, support team, or administrator rather than in casual everyday conversation.