Below query is still open in Emirates internal working group discussion list, even though SIS had tried to clarify it :
Query : When a Migrated carrier receives Prime billing from Non-Migrated carrier, the billing comes in IDEC format. Tax break up is not provided by the billing carrier. When this Prime billing is rejected, the Migrated carrier provides tax break up of accepted tax only, can the Migrated carrier put entire billed tax against one tax code and show the difference.
Reply from SIS - The rule will be that you need to put the tax under the individual appropriate tax codes.
Query from Emirates working group - The non migrated carrier billings will be received by the migrated carrier through the OLD IDEC file & in the old IDEC file there is no provision to be provide billed tax breakup. Since the migrated carrier will not receive the billed tax breakup, how will they provide the breakup during rejection stage.
Example : One one coupon, Non migrated carrier bills USD50 as tax without giving break up. Migrated carrier finds that it can accept USD10 against tax A, USD20 against tax B and USD15 against tax C. Balance USD5 need to be rejected. Against which tax code USD5 will be rejected. While rejecting, the migrated carrier need to provide rejected tax code in IS IDEC file. It does not know, the tax break up of USD100 as in IDEC, there is no provision for non migrated carrier to provide tax break up .