Just sharing my experience at Phitsanulok immigration office for my 90 day check in. I went a week before my 90 days and it was very easy. Only needed my passport and filled out form when I arrived, in and out in 10 minutes.
TLDR : Answer Summary
The user shares a positive experience regarding the 90-day check-in process at the Phitsanulok immigration office, noting that it was efficient and required only their passport and a simple form, taking about 10 minutes in total.