Same school, UKG to class 1, and they want a full admission form again

Our son finishes UKG and moves to class 1 in the same school this month. We've just been handed what looks like a fresh admission form: birth certificate, photos, address proof, Aadhaar copies, both parents' details, and a 'primary section admission fee'. Our daughter made the same move two years ago and I don't remember any of this, though it's possible my partner handled it and I've forgotten. Is this standard when children move from the pre-primary wing to primary? The paperwork is fine. I'd just like to know whether the fee is normal before I raise it with the office.