To file monthly Federal or Provincial Sales Tax returns in Pakistan, you typically need the following:

1. GST/PST Registration Certificate:

   • Proof of registration with the Federal Board of Revenue (FBR) for GST or the relevant provincial tax authority for PST.

2. Sales and Purchase Invoices:

   • Detailed records of all sales and purchase transactions for the month, including invoice numbers, dates, and amounts.

3. Input and Output Tax Details:

   • A breakdown of input tax (GST/PST paid on purchases) and output tax (GST/PST collected on sales) for the month.

4. Tax Payment Challan:

   • A copy of the payment challan for the sales tax due for the month, if applicable.

5. Adjustments and Credit Notes:

   • Details of any adjustments, credit notes, or debit notes issued during the month that affect the tax liability.

6. Business Bank Account Details:

   • Bank account information for remitting any tax due to the relevant authorities.

7. Previous Month’s Return:

   • A copy of the previous month’s tax return to ensure consistency and accuracy in reporting.

8. E-Filing Credentials:

   • Login details for the FBR’s IRIS portal or the relevant provincial e-filing system.

9. Taxpayer Profile:

   • Up-to-date information about the taxpayer’s business activities, address, and contact details as registered with the tax authority.