Плата за хранение уже оплачена.

Плата means fee, charge, or payment in the sense of an amount owed for a service.

In Плата за хранение уже оплачена, плата is the thing being talked about: the storage fee.

A useful distinction:

• плата = the fee/charge itself
• оплата = the act/process of payment

So:

• плата за хранение = storage fee
• оплата хранения = payment for storage / payment of storage charges

Both are possible in Russian, but this sentence is built around the fee as the subject.

Here за means for, and with this meaning it normally takes the accusative case.

So:

• плата за что? = fee for what?
• за хранение = for storage

The noun хранение is neuter singular, and its nominative and accusative forms are the same:

• nominative: хранение
• accusative: хранение

So even though the form does not change, it is still accusative here.

Хранение means storage, keeping, or safekeeping, depending on context.

It comes from the verb хранить = to store, to keep, to preserve.

In this sentence, за хранение is best understood as:

• for storage
• for keeping something in storage

So the whole phrase плата за хранение is a very natural way to say storage fee.

Because оплачена agrees with плата, and плата is:

• feminine
• singular

So the short passive participle must also be feminine singular:

• masculine: оплачен
• feminine: оплачена
• neuter: оплачено
• plural: оплачены

Compare:

• Счёт оплачен. = The bill has been paid.
• Плата оплачена. = The fee has been paid.
• Письмо отправлено. = The letter has been sent.

Оплачена is a short passive participle from the verb оплатить.

In sentences like this, short passive participles often express a resulting state:

• оплачена = paid
• закрыт = closed
• подписан = signed

So Плата за хранение уже оплачена means literally something like:

• The fee for storage is already paid
• more natural English: The storage fee has already been paid

This is a very common structure in Russian.

In the present tense, Russian usually does not use a verb meaning is/am/are.

So Russian says:

• Плата ... оплачена literally: The fee ... paid

but in English we must say:

• The fee is paid or more naturally here:
• The fee has been paid

The idea of a current result is understood from the participle and from context. The word уже also helps give the sense of already, which often sounds like English has already been.

Уже means already. Its position here is very natural and neutral:

• Плата за хранение уже оплачена.

It modifies the whole predicate: the fee is already paid.

Russian word order is flexible, but different orders can change emphasis a little. For example:

• Плата за хранение уже оплачена. = neutral
• Уже оплачена плата за хранение. = stronger focus on the fact that it has already been paid
• Плата уже оплачена. = shorter, if за хранение is understood

So the given order is standard and unmarked.

In this sentence, it is usually best translated as has been paid.

That is because Russian short passive participles often express a completed result that is true now.

So:

• Плата за хранение уже оплачена. most natural English:
• The storage fee has already been paid.

A more literal translation, The storage fee is already paid, is understandable but less natural in many contexts.

Yes, but the structure would normally change.

You would more naturally hear:

• За хранение уже заплачено. = Payment for storage has already been made / The storage has already been paid for.

This version is more impersonal. It does not make the fee the grammatical subject.

By contrast:

• Плата за хранение уже оплачена.

focuses specifically on the fee/charge as something that has been paid.

Both can work, but they are built differently.

The form оплачена comes from оплатить, which is a perfective verb meaning to pay in the sense of to settle a bill/fee.

Related forms:

• платить = to pay, to be paying
• заплатить = to pay
• оплатить = to pay for, to settle payment for something

A key pattern:

• оплатить что = to pay for something directly
  
  • оплатить счёт
  • оплатить проезд
  • оплатить хранение

So оплачена fits naturally with плата and with the idea that the charge has been settled.

Russian has no articles.

So Плата за хранение could mean:

• the storage fee
• a storage fee

Which one sounds right depends on context. In this sentence, English usually wants the:

• The storage fee has already been paid.

That sense comes from the situation, not from a separate word in Russian.

Yes, native speakers would absolutely say or write this. It sounds quite natural, especially in:

• business contexts
• invoices
• receipts
• storage facilities
• hotel or service situations
• official notices

It is slightly more formal or administrative than everyday casual speech, but still very normal.

In casual speech, someone might also say things like:

• Мы уже оплатили хранение. = We already paid for the storage.
• За хранение уже заплатили. = They/we already paid for the storage.

The original sentence sounds especially natural when the focus is on the status of the fee itself.