Pakistan's GST system operates on two tiers: Federal GST at 17% on goods (FBR under the Sales Tax Act 1990) and provincial Sales Tax on Services (Punjab PRA 16%, Sindh SRB 13%, KPK KPRA 15%, Balochistan BRA 15%). Understanding both tiers and the critical difference between tax-exclusive and tax-inclusive calculation is essential for businesses and consumers. ## Tax-Exclusive vs Tax-Inclusive — The Critical Calculation Tax-exclusive (add tax to base price): Total = Base x (1 + Rate/100). For Rs. 10,000 base at 17%: GST = Rs. 1,700, Total = Rs. 11,700. Tax-inclusive (extract tax from total): GST = Total x Rate / (100 + Rate). For Rs. 11,700 total at 17%: GST = Rs. 11,700 x 17/117 = Rs. 1,700, Base = Rs. 10,000. The critical error: multiplying Rs. 11,700 x 17% = Rs. 1,989 is WRONG for a tax-inclusive price. Always use Rate/(100+Rate) for inclusive extraction. Our calculator handles both modes correctly — select your mode before calculating. ## Zero-Rated vs Exempt Goods Zero-rated (0%, suppliers can claim input tax refunds): All exports, unpackaged basic food (loose rice, wheat, pulses, vegetables, fruits), most medicines, agricultural inputs. Exempt (0%, no input tax refund): Real estate transactions, financial services, education, health services. ## Input Tax Credit — How the Value-Added Mechanism Works Input Tax Credit prevents cascading taxation. Each registered seller claims credit for GST paid on inputs, paying only the net GST on the value they added. A manufacturer paying Rs. 17,000 GST on inputs and charging Rs. 34,000 GST on output pays only Rs. 17,000 to FBR. For ITC to be claimable: purchase must be for business use; supplier must have filed their monthly return correctly; valid tax invoice with supplier's STRN required. ## Monthly Filing Obligations Registered businesses file monthly GST returns at iris.fbr.gov.pk by the 18th of each subsequent month. Declaring output tax, input tax, and paying net liability. Persistent non-filing leads to STRN suspension — blocking valid tax invoice issuance and preventing customers from claiming ITC on your sales.