Provisional assessment timelines require expeditious finalisation under specified customs regulations, with project imports governed separately. Finalisation of provisional assessment must be completed expeditiously under the Customs (Finalisation of Provisional Assessment) Regulations, 2018, which set timelines and manner for concluding such assessments. Project imports are excluded from that regime and must be finalised under the Project Import Regulations, 1986, as amended; earlier notifications and circulars provide procedural references but do not alter these primary regulatory obligations.