Thank you!
So for my N-400, this would be the field office but for my I-751, it would be Potomac service center.
I have a notice saying my case was transferred to the National Benefits Center a while back (September 2022).
For N-400, 80% case processing times are 15 months. My receipt date is May 23, 2022. By that logic, I can contact them about my case 15 months after the receipt date (August 24, 2023), right? Well, when I enter this in their case processing tool and earliest inquiry date, they give me a date of May 24, 2024.