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not-my-department

/nɒt maɪ dɪˈpɑːt.mənt/
IELTSAcademic
idiom

Used to say that something is not your responsibility or area of work. It can sound casual, and sometimes a little rude or dismissive.

  • That issue is not my department.
  • Sorry, that's not my department.
  • Accounting said it was not my department.

Adinary Nuance

Not my department is more about responsibility than knowledge. It is closer to "not my job" than to "I don't know," but it can sound sharper than both. Use it when you want to say the issue belongs to someone else, not when you simply lack information. In polite business English, "I’m not the right person to ask" often sounds softer.

In other languages

Vietnamese
không phải việc tôi
Spanish
no es mi responsabilidad
Chinese
不归我管
Japanese
私の担当ではない
Korean
내 담당이 아니다

Etymology

This phrase comes from workplace and office English, where a department is a specific team or division. It became a fixed idiom in modern business speech.

Common phrases

that's not my departmentit's not my departmentsorry, not my department

Synonyms

Related words

Frequently asked questions

Is "not my department" polite?
It can sound neutral, but it may also sound dismissive. Use a softer phrase in formal situations.
What is the difference between "not my department" and "I don't know"?
"Not my department" means it is outside your responsibility. "I don't know" only says you do not have the answer.
Can I use "not my department" in emails?
Yes, but it can sound blunt. In email, a softer reply is often better.
Is "not my department" common in business English?
Yes, it is common in office and workplace conversation, especially spoken English.