Customs refund procedure requires documentary proof; refunds may be transferred to Consumer Welfare Fund unless incidence not passed on. Applications for refunds require documentary evidence proving excess payment and non-passing on of the duty or interest. Customs acknowledges complete applications and returns incomplete ones for correction. Complete applications are processed to determine refundable duty and interest, and orders for refund are issued where appropriate. Refunds are governed by the unjust enrichment principle and are generally transferred to the Consumer Welfare Fund unless specific exceptions apply, including non-passing on of incidence, personal use imports, returned export goods, drawback claims, notified classes bearing duty, and evident excess payments on bills of entry.