Ввиду того, что срок сдачи близок, поэтапную оплату проверят.

It means since, because, or more formally in view of the fact that.

This is a fairly formal, written-style connector. In everyday speech, Russian speakers are more likely to use потому что, так как, or из-за того, что.

So the sentence has an official or business-like tone right from the start.

Because ввиду as one word means because of or in view of.

That is different from в виду as two words, which usually appears in expressions like иметь в виду = to have in mind / to mean.

So in this sentence, only ввиду is correct.

The sentence contains a subordinate clause of reason:

ввиду того, что срок сдачи близок

The commas show where that clause is set off from the main clause. In formal written Russian, you will very often see ввиду того, что written with a comma before что, and then another comma closes the whole reason clause before the main clause begins.

So the structure is basically:

Because X, Y will happen.

Срок сдачи is a common expression meaning submission deadline, due date, or deadline for handing something in.

Grammatically:

• срок = deadline, term, time limit
• сдачи = genitive singular of сдача

Russian often uses this pattern:

• срок оплаты = payment deadline
• срок выполнения = completion deadline
• срок доставки = delivery deadline

So сдачи is in the genitive because it specifies the deadline of what.

Близок is the short-form adjective of близкий.

In Russian, short-form adjectives are often used as the predicate, especially in formal or concise language:

• срок близок = the deadline is near
• результат готов = the result is ready
• вопрос ясен = the question is clear

Here близок agrees with срок, which is masculine singular.

So:

• близкий would usually be the full form used before a noun
• близко is an adverb and would not fit this structure

Yes, especially in formal or written Russian.

It means the deadline is near or approaching. A more conversational version might use something like срок сдачи скоро or срок сдачи уже скоро, but срок сдачи близок is perfectly normal in formal style.

Поэтапная оплата means payment in stages, phased payment, or sometimes installment-style payment, depending on context.

The adjective поэтапный comes from этап = stage, phase. So the idea is that the payment is divided into several steps rather than made all at once.

It does not necessarily mean fixed monthly installments; it more generally means payment broken up by stages or phases.

Because it is the direct object of проверят.

The verb проверить / проверять takes the accusative case, so:

• поэтапная оплата = nominative
• поэтапную оплату = accusative

Both the adjective and the noun change:

• поэтапная → поэтапную
• оплата → оплату

Russian often uses the 3rd person plural with no explicit subject to mean an unspecified agent, similar to English they in sentences like They checked it where they does not refer to specific people.

So проверят here means something like:

• they will check it
• it will be checked by the relevant people
• the responsible side will review it

This is very common in administrative, official, and business Russian.

Проверят is the future tense of the perfective verb проверить.

That means the sentence presents the action as a single complete future event: they will check it, and the checking will be completed.

Compare:

• проверят = they will check / verify
• будут проверять = they will be checking

The first sounds more definite and result-oriented.

In this kind of context, it often means review, verify, or confirm, not necessarily physically inspect something.

In business or administrative Russian, проверить оплату can mean checking payment details, confirming whether payment terms are acceptable, or reviewing the payment arrangement.

So the exact English word depends on context, but check is only the most literal starting point.

Yes, it is natural, especially in formal written Russian.

Russian word order is flexible. Putting поэтапную оплату before проверят is normal and slightly highlights the object. It also gives the sentence a formal, document-like rhythm.

A more neutral order would also be possible:

... проверят поэтапную оплату.

Both are grammatical, but the original sounds more official.

Yes, definitely.

The formal tone comes from several things working together:

• ввиду того, что instead of a simpler потому что
• срок сдачи близок, which is concise and written-style
• the unspecified проверят
• the object-before-verb order поэтапную оплату проверят

So this sounds much more like business, legal, or administrative Russian than casual conversation.