Who Must File a Monthly Sales Tax Return?

Every person registered for sales tax (holding an STRN) — manufacturers, importers, wholesalers, distributors, and Tier-1 retailers — must file a monthly sales tax return regardless of whether there was any taxable activity that month. Even with zero sales, a "nil return" must be filed.

Monthly Filing Timeline

StageDeadlineWhat's Submitted
Annexure-C10th of next monthSales invoice data
Tax Payment15th of next monthPayment via bank/online challan
ST-3 Return18th of next monthFinal return with input/output tax reconciliation

Missing any of these three steps triggers a default surcharge (interest-like penalty) and may attract a penalty notice. Annexure-C, in particular, is often missed by businesses unfamiliar with the two-stage filing structure.

Input Tax vs Output Tax

  • Output tax — sales tax you charge customers on your sales (typically 18%, or 16%/13%/15% provincial for services)
  • Input tax — sales tax you paid on purchases/inputs, which can be adjusted (deducted) against your output tax
  • Net payable — output tax minus adjustable input tax equals the amount you pay to FBR for that month

Input tax adjustment requires valid sales tax invoices from properly registered suppliers. Certain items are on FBR's "blocked" list and cannot be adjusted even with a valid invoice — for example, tax on certain vehicles or non-business-related purchases.

Penalties for Late or Non-Filing

DefaultPenalty
Late filing of returnRs. 10,000 or 0.1% of tax payable per day, whichever is higher (capped)
Non-payment of taxDefault surcharge (KIBOR-based) plus penalty
Persistent non-filingRisk of audit, suspension/blacklisting of STRN

Frequently Asked Questions

What is the deadline for filing monthly sales tax return?
Annexure-C (sales data) must be submitted by the 10th, payment by the 15th, and the final ST-3 return by the 18th of the following month. Missing any of these deadlines triggers penalties and default surcharge.
Can I adjust input tax against output tax?
Yes. Registered persons can adjust input tax (tax paid on purchases) against output tax (tax charged on sales) in the same return, provided the input tax is supported by valid sales tax invoices from registered suppliers and is not on the blocked/non-adjustable list.
What happens if I file a nil return every month with no real activity?
FBR closely monitors registered persons who consistently file nil returns despite being registered for sales tax — this can trigger an audit or de-registration notice, since registration implies an expectation of taxable activity.

Need Monthly Sales Tax Filing Support?

We handle Annexure-C, payment challans, and ST-3 returns every month so you never miss a deadline.