Согласование проекта завершат вне зависимости от поэтапной оплаты.

Because согласование проекта is not the subject here. The sentence uses an indefinite-personal construction: the subject is omitted, and the verb in 3rd person plural means something like they will complete or it will be completed by someone.

So the structure is essentially:

[They] will complete the project approval, regardless of phased payment.

In other words:

• завершат = they will complete
• согласование проекта = the thing being completed

The main clue is the verb form завершат.

If согласование were the subject, the verb would have to match it as singular neuter, for example:

• Согласование проекта завершится = the approval process will be completed / will finish
• Согласование проекта будет завершено = the approval will be completed

But here we have завершат, which is plural, so Russian is signaling an omitted they.

Also, согласование has the same form in nominative and accusative because it is an inanimate neuter singular noun. So only the verb really tells you its role here.

Because for inanimate neuter singular nouns, the accusative form is the same as the nominative form.

So:

• nominative: согласование
• accusative: согласование

That is completely normal in Russian. English speakers often expect the object to look different, but in Russian it often does not.

Because согласование is a verbal noun, and Russian often uses the genitive after such nouns to show what is being acted on.

So:

• согласование чего? = approval / coordination of what?
• проекта = of the project

This is very common with nouns derived from verbs. Compare:

• обсуждение вопроса = discussion of the issue
• подписание договора = signing of the contract
• согласование проекта = approval / coordination of the project

It is a deverbal noun: a noun made from a verb.

It comes from verbs like:

• согласовать
• согласовывать

Instead of using a full verb clause, Russian business and official style often prefers nouns like this. That makes the sentence sound more formal and bureaucratic.

A less noun-heavy version might be something like:

• Проект согласуют...
• Проект будет согласован...

But согласование проекта is very typical in formal written Russian.

It is a fixed expression meaning regardless of, irrespective of, or independently of.

Literally, it is built from:

• вне = outside
• зависимости = dependence
• от = on / from

But you should learn it as one set phrase:

вне зависимости от + genitive

Examples:

• вне зависимости от обстоятельств = regardless of the circumstances
• вне зависимости от времени = regardless of the time
• вне зависимости от оплаты = regardless of payment

Because от requires the genitive case.

So the noun becomes:

• nominative: поэтапная оплата
• genitive: поэтапной оплаты

And the adjective поэтапной must agree with оплаты in:

• gender
• number
• case

That is why both words change.

Поэтапной means phased, stage-by-stage, or in installments/stages, depending on context.

It comes from поэтапный, literally something like by stages.

So поэтапная оплата is payment made in separate stages rather than all at once.

This is common in contracts, construction, business, and project management language.

Завершат is the simple future of the perfective verb завершить.

That tells you the speaker views the action as a completed whole:

• завершат = they will complete / they will finish

Because it is perfective, it focuses on the result: the approval process will reach completion.

If you used the imperfective instead, you would get something like:

• будут завершать

That would mean will be in the process of completing, which does not fit as well here.

Russian often uses 3rd person plural with no stated subject to talk about actions when the doer is unknown, unimportant, or deliberately unstated.

So:

• Согласование проекта завершат... = they will complete the project approval...

  This often feels close in English to a passive:

• The project approval will be completed...

A passive Russian version would be:

• Согласование проекта будет завершено вне зависимости от поэтапной оплаты.

Both are possible. The original version is natural and common in administrative or business language.

Yes, the word order is normal, especially in formal writing.

The original order:

Согласование проекта завершат вне зависимости от поэтапной оплаты.

puts the focus first on what will be completed, and then adds the condition/qualification.

You could also say:

• Вне зависимости от поэтапной оплаты согласование проекта завершат.

That version foregrounds regardless of phased payment.

Russian word order is flexible, but different orders shift emphasis slightly.

Yes, very formal.

The features that make it sound official or business-like include:

• the noun согласование
• the set phrase вне зависимости от
• the abstract phrase поэтапная оплата
• the unstated-agent structure завершат

This is exactly the kind of sentence you might see in:

• contracts
• project documentation
• internal corporate communication
• legal or administrative writing

In everyday speech, people might choose a simpler wording.