I'm afraid there's been a mistake.

Meaning

Politely pointing out an error.

Examples

• John: Your invoice is incorrect.
• Alice: Oh dear, <b>I'm afraid there's been a mistake</b>. I apologize for the error.
• John: Can you please correct it?
• Alice: Of course, I'll send you a corrected version immediately. Yes, <b>I'm afraid there's been a mistake</b>.