Registration under section 12AB: electronic application, inquiry rules and written grant with Unique Registration Number. Registration of charitable, religious and educational trusts under the amended regime requires electronic application in the prescribed forms for initial, provisional, renewal or conversion to regular registration. The tax authority must pass a written order granting registration for a fixed term or reject and cancel after hearing; certain cases proceed without inquiries while others permit document requests to verify genuineness of activities and compliance. Grants are evidenced by a written certificate and an alphanumeric Unique Registration Number; filing windows, decision timelines and electronic verification rules apply, and delays may be condoned for reasonable causes.