In-app report (fastest)
- Open the impersonating profile → tap the ⋯ menu → Report.
- Choose 'It's pretending to be someone else' → 'Me'.
- Submit. In-app reports from the impersonated person are weighted heavily.
Official impersonation form
If the in-app report stalls, use Instagram's impersonation web form. You'll need a photo of your government ID to prove you're the real person. This is the most reliable path.
Copyright option
If the account is re-posting your actual photos/videos, you can also file an Instagram copyright report — that targets the content rather than the identity and is useful when ID verification is slow.