technically, top 5 invoices or each category for entire period should suffice. we have seen practicle scenarios where FTA has requested the refund templates for each period separately. The FTA would seek additional requirements during resubmission if it needs more documents. Thus, in my view, a single refund template should be uploaded withi top 5 invoices for the entire period. however, invoices for each tax period should be kept ready in case FTA requests.