bansongdoen mulgeone jeopsu beonhoreul jeogeossseupnida.

반송된 is a modifier meaning returned or sent back.

It comes from:

• 반송하다 = to send back, return
• 반송되다 = to be sent back, to be returned
• 반송된 = the form used before a noun, meaning that was returned

So:

• 반송된 물건 = the returned item / the item that was sent back

This is a very common Korean pattern:

• verb stem + -ㄴ / -은 before a noun
• it often works like the ... that did X or the ... that was X-ed

So 반송된 물건 literally feels like the item that was returned.

Because 에 marks the place or surface where something is written.

In this sentence, the pattern is:

• A에 B를 적다 = to write B on/in A

So here:

• 물건에 = on the item
• 접수 번호를 = the receipt/registration number
• 적었습니다 = wrote

So the item is not the direct object. It is the location/surface where the writing was made.

Compare:

• 종이에 이름을 적었습니다. = I wrote my name on the paper.
• 물건에 접수 번호를 적었습니다. = I wrote the receipt number on the item.

Because 접수 번호 is the thing that was written.

With 적다 in this sense, the thing being written takes 을/를.

So:

• 물건에 = where it was written
• 접수 번호를 = what was written

This is exactly the same logic as:

• 벽에 글자를 적었다 = wrote letters on the wall
• 서류에 주소를 적었다 = wrote the address on the document

접수 번호 usually means a number given when something is officially received, filed, accepted, or registered.

Depending on context, it could be translated as:

• receipt number
• registration number
• reference number
• intake number

The parts are:

• 접수 = reception, acceptance, filing, registering
• 번호 = number

So it is a practical administrative label, not just any random number.

Both relate to writing, but 적다 is often used when you mean write down, note, or record specific information.

So 접수 번호를 적었습니다 sounds natural because a number is being written down as information.

Roughly:

• 적다 = write down, jot, record
• 쓰다 = write, use, wear, spend, and other meanings depending on context

In many situations, 쓰다 could also work, but 적다 often sounds more natural for things like:

• names
• phone numbers
• addresses
• ID numbers
• receipt numbers

So this sentence has a practical, clerical feel, and 적었습니다 fits that well.

적었습니다 is:

• past tense
• formal polite style (-습니다 style)

So it is suitable for:

• formal writing
• reports
• workplace speech
• polite explanations
• official situations

Related forms:

• 적었습니다 = wrote
• 적어요 = write / am writing / write politely in casual polite speech
• 적었어요 = wrote, casual polite
• 적었다 = wrote, plain form

It can be either, depending on context.

Korean often does not mark singular vs. plural unless it is necessary.

So 물건 can mean:

• item
• items
• thing
• things

And 반송된 물건에 접수 번호를 적었습니다 could refer to:

• one returned item
• returned goods in a general sense
• one specific package/item in context

If Korean wants to be explicitly plural, it might use something like 물건들, but very often that is unnecessary.

Because Korean often leaves out the subject when it is already understood from context.

So this sentence does not say explicitly who wrote the number, but it is usually understood as something like:

• I wrote
• we wrote
• someone wrote

depending on the situation.

If the speaker wanted to include the subject, they could say:

• 제가 반송된 물건에 접수 번호를 적었습니다. = I wrote the receipt number on the returned item.
• 저희가 반송된 물건에 접수 번호를 적었습니다. = We wrote the receipt number on the returned item.

Omitting the subject is very normal in Korean.

Yes. Korean word order is flexible as long as the particles make the roles clear.

This sentence uses a very natural order:

• 반송된 물건에 접수 번호를 적었습니다

But you could also say:

• 접수 번호를 반송된 물건에 적었습니다

That still means basically the same thing, but it puts a little more emphasis on 접수 번호.

Because of the particles:

• 에 tells you where
• 를 tells you what was written

the meaning stays clear even if the order changes.

Here it means on the returned item.

The particle 에 can have different meanings depending on the verb, such as:

• location
• destination
• time
• target

With 적다 meaning to write, 에 usually marks the place or surface where the writing appears.

So in this sentence, the natural interpretation is:

• on the returned item
• possibly on/in the returned package, depending on context

It does not mean that the number was sent to the item.

Yes, it does.

반송된 comes from 반송되다, which has the sense to be returned / to be sent back.

So the item is being described as something that was returned, not as something that actively returned itself.

That passive nuance is built into the word.

A learner might compare:

• 반송한 물건 = the item that someone sent back
• 반송된 물건 = the item that was sent back / returned

In real usage, 반송된 물건 is the natural way to describe an item that has been returned.