syainsyou wo keitaisuru koto ni natte imasu.

It is read:

しゃいんしょう を けいたいする こと に なって います。

A natural pronunciation is:

shainshou o keitaisuru koto ni natte imasu

Notes:

• 社員証 = しゃいんしょう
• 携帯する = けいたいする
• なって comes from なる

社員証 means an employee ID card or staff ID badge.

It breaks down like this:

• 社員 = employee, staff member
• 証 = certificate, proof, pass

So 社員証 is the card or badge that proves you are an employee.

を marks the direct object of the verb.

Here, the verb is 携帯する, which means to carry on one’s person or to have with oneself. So 社員証を携帯する means:

• to carry an employee ID
• literally, to carry the employee ID card

So を is there because 社員証 is the thing being carried.

携帯する is more formal and more specific in tone.

Comparison:

• 持つ = to hold, to have, to carry
• 携帯する = to carry with you, to keep on your person

In company rules, notices, manuals, and official language, 携帯する sounds more appropriate than 持つ. It gives the sentence a formal, rule-like tone.

So this sentence sounds like something you would see in:

• company regulations
• workplace instructions
• official notices

Here, こと turns the verb phrase into a noun-like idea.

So:

• 携帯する = to carry
• 携帯すること = carrying it / the act of carrying it

This noun-like phrase can then be used with grammar such as ことになる or ことになっている.

In other words, こと lets the whole action become the topic of a rule or arrangement.

ことになっています is a very common pattern meaning:

• it has been مقرر as a rule
• it is arranged that...
• it is the rule that...
• one is supposed to...

In this sentence, it means that carrying the employee ID is an established rule or arrangement.

Important nuance:

• It usually does not sound like the speaker personally decided it.
• It sounds like a company policy, social rule, system, or predetermined arrangement.

So the sentence has the feeling of:

• Employees are required to carry their ID cards
• The rule is that employees must carry their ID cards

This comes from the pattern:

dictionary form + ことになる

which literally has the sense of it becomes the case that... or it is decided that...

Structure:

• 携帯すること = the act of carrying it
• になる = to become
• 携帯することになる = it becomes the case that one carries it / it is decided that one must carry it

Then in the sentence:

• ことに is part of that grammar pattern
• it is not a separate meaning like for or to in the usual sense

So the に is just part of ことになる / ことになっている.

〜ことになっている describes a rule or arrangement that is currently in effect.

Compare:

• ことになる
  = it will be decided / it comes to be decided

• ことになった
  = it was decided

• ことになっている
  = it has been decided and that decision is now in force; it is the standing rule

So なっています shows a continuing state. The rule has already been established, and it still applies now.

That is why ことになっています is especially common in:

• rules
• procedures
• schedules
• instructions

This is a very common learner question.

ことになっています

This usually means:

• it has been decided
• it is the rule
• it is set up that way

The decision often comes from:

• an organization
• a system
• social rules
• circumstances
• some external arrangement

ことにしています

This usually means:

• I make it a rule to...
• I have decided to...
• I try to always...

This sounds like a personal habit or self-imposed rule.

Examples:

• 毎朝、運動することにしています。
  = I make it a rule to exercise every morning.

• 社員証を携帯することになっています。
  = It is the rule that employees carry their ID cards.

So in your sentence, なっています shows an external rule, not a personal choice.

Japanese often leaves out the subject when it is obvious from context.

In a workplace notice, 社員証を携帯することになっています naturally implies something like:

• employees
• staff members
• people in this company

A fuller version could be:

• 社員は社員証を携帯することになっています。
• 当社の社員は社員証を携帯することになっています。

But Japanese usually omits that if the context already makes it clear.

Yes, it is fairly formal.

Reasons:

• 社員証 is workplace vocabulary
• 携帯する is a formal verb
• ことになっています is a standard formal pattern for rules and arrangements
• います gives it a polite form

This is exactly the kind of phrasing you would expect in:

• employee handbooks
• office signs
• company emails
• administrative instructions

A more casual version might use different wording, but this one sounds official and professional.

Yes.

Even though the sentence does not use a direct obligation pattern like:

• 〜なければならない
• 〜なくてはいけない

it still strongly implies obligation because ことになっています is often used for official rules.

So in practice, this sentence can function very much like:

• You must carry your employee ID
• Employees are required to carry their ID cards

The difference is in tone:

• 〜なければならない sounds like a direct statement of necessity
• 〜ことになっています sounds like stating an established rule or policy

So this sentence is a bit more indirect and institutional in tone.

You can use that as a rough way to understand the grammar, but it is not natural English.

A grammar-based literal breakdown is:

• 社員証を携帯する = carry an employee ID
• こと = the act / fact of doing that
• になっている = has become the standing state / has been arranged

But in natural English, you would usually say something like:

• Employees are supposed to carry their ID cards
• It is company policy to carry your employee ID
• Employees are required to carry their employee ID cards

So the literal breakdown is useful for studying, but not for final translation.