FBR Sales Tax Return Annexure-C Guide (2026)

Master FBR sales tax filing on Iris 2.0. Learn Annexure-C invoice upload, Section 8B 90% input tax restriction, CREST discrepancy resolution, and deadlines.

By Syed Asad Hussain Zaidi · 8 September 2026

Author Note / Last Updated: Updated September 2026 by Syed Asad Hussain Zaidi | Advocate High Court | Senior Indirect Tax & Corporate Litigation Counsel. In Pakistan’s commercial landscape, managing sales tax compliance is vastly more volatile and operationally demanding than annual corporate income tax. Governed primarily by the Sales Tax Act, 1990 (STA 1990) and synchronized across the Federal Board of Revenue’s (FBR) digital Iris 2.0 portal, sales tax operates as a destination-based, invoice-driven value-added tax (VAT). Every registered manufacturer, importer, wholesaler, distributor, and Tier-1 retailer in Pakistan must navigate an aggressive monthly compliance cycle. Under this regime, the most critical, high-risk document is Annexure-C (Domestic Supplies). Annexure-C is not a passive summary; it is an itemized, invoice-by-invoice transaction database where the seller reports every commercial invoice issued to every customer. If you make a clerical error in a buyer’s National Tax Number (NTN), misclassify a Harmonized System (HS) code, or fail to submit Annexure-C before the statutory deadline, your buyers cannot claim input tax credit on their purchases from you. Furthermore, FBR’s automated CREST (Computerized Risk-based Evaluation of Sales Tax) engine continuously cross-examines Annexure-C against buyer declarations in real time. A single mismatch between Annexure-A and Annexure-C triggers automatic show-cause notices, input tax disallowances, and potential suspension of sales tax registration under Rule 12 of the Sales Tax Rules, 2006. This comprehensive guide delivers an authoritative analysis of monthly sales tax return filing on Iris 2.0, Annexure-C invoice mechanics, the Section 8B 90% input tax limitation, and CREST discrepancy resolution. --- Statutory Architecture: Value Added Tax (VAT) Mechanics in Pakistan The economic foundation of the Sales Tax Act, 1990 rests on the continuous offset of Input Tax against Output Tax: The Strict Monthly Filing Calendar: Unlike income tax returns filed annually, sales tax operates on a strict monthly cycle: The 15th of the Month (Payment Deadline): The net payable sales tax must be deposited into the National Bank of Pakistan (NBP) or via State Bank digital payment mechanisms (PSID / 1Link) on or before the 15th day of the following month. The 18th of the Month (E-Filing Deadline): The complete monthly return (Form STR-7) must be electronically submitted on Iris 2.0 on or before the 18th day of the month. --- Anatomy of Annexure-C: The Digital Supply Ledger Annexure-C is the foundational data feed that powers the entire national sales tax matching matrix. When completing Annexure-C on Iris 2.0, every single commercial transaction must be recorded with exact statutory precision: Critical Field Requirements: Buyer Registration Status: If the buyer is an active registered filer on the FBR Sales Tax Active Taxpayer List (ATL), input their NTN. If selling to an unregistered business entity or end-consumer whose purchase exceeds PKR 100,000, their CNIC number must be recorded under Section 23(1)(b). Further Tax (Section 3(1A)): If a registered manufacturer or wholesaler makes taxable supplies to an unregistered commercial person, the seller is statutorily mandated to charge an additional 4% Further Tax over and above the standard 18% sales tax rate (totaling 22%). Failing to charge Further Tax on unregistered B2B sales results in immediate recovery notices during audit. --- The Devastating Trap of Section 8B: The 90% Input Tax Limitation The single greatest source of cash-flow friction for Pakistani manufacturers and distributors is Section 8B of the Sales Tax Act, 1990: Mathematical Demonstration of Section 8B: Suppose a manufacturing company in Gujranwala reports the following in a given month: Output Tax on Sales (Annexure-C): PKR 1,000,000 Total Valid Input Tax on Purchases (Annexure-A): PKR 1,200,000 Under pure VAT logic, the company would pay zero tax and carry forward PKR 200,000. Under Pakistani Section 8B, this is illegal. Maximum allowable input tax adjustment: $90\% \text{ of Output Tax} = 90\% \times \text{PKR } 1,000,000 = \text{PKR } 900,000$. Mandatory Cash Sales Tax Payable: $\text{PKR } 1,000,000 - \text{PKR } 900,000 = \text{PKR } 100,000$ (Must be paid in cash!). The remaining unadjusted input tax (PKR $1,200,000 - 900,000 = \text{PKR } 300,000$) is carried forward to the following month under Section 10. Who is Exempt from Section 8B? Under SRO notifications, certain sectors are exempt from the 90% restriction and can claim 100% input adjustment: Public listed companies traded on the Pakistan Stock Exchange (PSX). Zero-rated export manufacturers under Section 4. Companies whose inputs consist of petroleum products or fixed capital assets (machinery). --- The CREST Risk Engine: How Mismatches Trigger Registry Suspension The Federal Board of Revenue operates CREST (Computerized Risk-based Evaluation of Sales Tax), an automated surveillance engine integrated into Iris 2.0: The Section 73 Banking Mandate (Crossed Cheques & Digital Accounts): Under Section 73 of the Sales Tax Act, 1990, payment for all business purchases exceeding PKR 50,000 must be executed through a crossed banking instrument (cheque, pay order, direct online banking transfer) from the designated business bank account of the buyer to the designated business bank account of the seller! LEGAL CONSEQUENCE OF CASH PURCHASES: If a company purchases raw materials for PKR 500,000 and pays in cash, Section 73 disallows the entire input tax credit, even if the invoice is 100% genuine and correctly reported on Annexure-C! The buyer loses both their sales tax input credit and their income tax expense deduction under Section 21(l). --- Federal Goods Sales Tax (FBR) vs. Provincial Services Sales Tax (PRA, SRB, KPRA, BRA) Following the 18th Constitutional Amendment, the taxation of services was devolved to the four provincial revenue authorities: Sindh Revenue Board (SRB): Sindh Sales Tax on Services Act, 2011. Punjab Revenue Authority (PRA): Punjab Sales Tax on Services Act, 2012. Khyber Pakhtunkhwa Revenue Authority (KPRA): KP Finance Act, 2013. Balochistan Revenue Authority (BRA): Balochistan Sales Tax on Services Act, 2015. --- End-to-End Monthly Sales Tax Filing Walkthrough on Iris 2.0 To execute a flawless monthly submission on the FBR portal, follow this systematic workflow: Upload Annexure-C Early (Before the 10th): Upload your outward invoices early in the month. This ensures your corporate buyers can see the invoices on their Annexure-A and process payments to you without withholding disputes. Review Annexure-A (Purchases): Check all purchase invoices entered by your suppliers. Reject any bogus or unfamiliar invoices to prevent CREST fraud investigations. Calculate Section 8B Impact: Check the automated calculation tab. Confirm whether the 90% limitation applies, and ensure sufficient liquidity to pay the mandatory 10% cash minimum. Generate PSID Challan: Create the electronic payment challan on Iris 2.0 under code and deposit the funds before the 15th. Final Submission: Link the Computerized Payment Receipt (CPR) to the return and click "Submit" before midnight on the 18th. --- Monthly Sales Tax Compliance Checklist for Chief Accountants Before authorizing the monthly sales tax submission, execute this operational audit: [ ] Verify Buyer NTNs on FBR ATL: Ensure all B2B buyers have active, valid NTNs; confirm CNICs are entered for unregistered buyers exceeding statutory thresholds. [ ] Audit Section 73 Banking Compliance: Confirm all purchase payments exceeding PKR 50,000 were transferred through crossed banking channels from your registered corporate bank account. [ ] Enforce 4% Further Tax: Verify that 4% Further Tax was charged on all supplies made to unregistered commercial entities. [ ] Apply Section 8B Limitation: Account for the mandatory 10% cash payment requirement on output tax unless specifically exempt under SRO circulars. [ ] Review CREST Dashboard: Audit the "Discrepancy Alerts" tab on Iris 2.0; resolve any invoice mismatches before they mature into formal show-cause notices. [ ] Meet Both Deadlines: Deposit tax on or before the 15th, and submit the return on or before the 18th to prevent automated non-filer late penalties. --- Conclusion: Eliminating Sales Tax Risk on FBR Iris 2.0 Monthly sales tax compliance in Pakistan is a high-speed, zero-margin-for-error discipline. A single defective invoice in Annexure-C or an unverified cash payment under Section 73 can dismantle your entire supply chain, triggering input tax disallowances, CREST audit notices, and registration suspension. By mastering the electronic invoice architecture of Annexure-C, managing the cash flow impact of the Section 8B 90% rule, and enforcing strict crossed-banking payment protocols, corporate enterprises can maintain unassailable sales tax compliance across Pakistan. For corporate sales tax structuring, resolving CREST discrepancy notices, or defending against FBR sales tax audit orders, contact our Indirect Tax Practice Group at TaxCalc.pk / Zaidi & Associates.