Udhaar (Credit Sales) and FBR Digital Invoicing: The Section 73 Rule — Rs 50,000, Bank Payment and 180 Days (2026)
Credit sales do not delay the FBR invoice. Section 73: over Rs 50,000 a month to one supplier must be paid by bank within 180 days, or input tax is lost.
The short version
This page is for anyone who sells on udhaar (credit — the buyer takes the goods now and pays later). It answers two questions. Does udhaar change when you send the invoice to FBR? And how, and how soon, must the buyer pay?
Udhaar does not delay the invoice. You post the digital invoice to FBR when the goods are delivered, not when the money comes in. The payment has its own rule, Section 73 of the Sales Tax Act 1990. Once a buyer's purchases from one supplier cross Rs 50,000 in a tax period (one month), payment must go through a bank. It must move from the buyer's declared business bank account to the seller's. On a credit sale, that bank payment must arrive within 180 days of the invoice date.
Break either rule and the buyer loses the input tax (the sales tax already paid on purchases, which a registered business subtracts from the tax it owes) on that purchase. The Rs 50,000 test used to be counted bill by bill. The Finance Act 2024 changed it to the monthly total per supplier. Many businesses still count it the old way.
Does udhaar change the invoice date? No
FBR taxes the sale, not the collection. The invoice date is fixed by the time of supply (the date the law says a sale happened, usually when the goods are delivered). On a credit sale that is the delivery date. 'When Must You Issue an FBR Digital Invoice? Time of Supply, Advance Payments and the Whichever-Is-Earlier Rule (2026)' works through the cases.
The FBR digital invoice has no field for a due date or payment terms. FBR records the sale and the tax on it, not when the buyer will pay. The sales tax on that invoice goes into the return for the month of the invoice date, and you pay it with that return. 'How Digital Invoicing Feeds Your Sales Tax Return (Annexure-C) in 2026' shows the flow.
There is no sales tax relief for an unpaid invoice. If the buyer never pays, the tax is still due, and non-payment is no reason to cancel the invoice or raise a credit note. Holding the invoice back until the money arrives only makes the sale un-invoiced and late, the problem covered in 'What Happens If an FBR Digital Invoice Is Generated Late? Backdating, Penalty and the Fix (2026)'.
What Section 73 actually says, in plain words
Section 73 is titled 'Certain transactions not admissible'. It has three working parts. Part one is the payment method. Once payments to one supplier in a tax period pass Rs 50,000, they must be made by crossed cheque, bank draft, pay order or another crossed banking instrument. A crossed instrument can only go into an account, never be cashed at the counter. The money must leave the buyer's business bank account and reach the seller's. Utility bills are excluded from the test.
Two provisos (extra conditions attached to the rule) widen what counts as a bank payment. An online transfer between the two business accounts counts, and so does a credit card payment, if both bank statements can prove it. Since the Finance Act 2021, two businesses that owe each other money may also set one debt off against the other. That needs both sides to have charged and paid the sales tax involved, plus the Commissioner's approval in advance.
Part two is the penalty side. A buyer who pays any other way loses the right to claim input tax, an adjustment, a refund or zero-rating on that purchase. For a transaction on credit, the payment must be transferred within 180 days of the date the tax invoice was issued. Part three points at the seller. The money must land in the seller's business bank account, or the seller loses input tax on its own side.
A business bank account is not just any account. It is the account the registered person uses for business and has declared to the Commissioner, on Form STR-1 or by updating registration particulars. An account you never declared does not count, even in the company's name. 'Sales Tax Registration (STRN) in Pakistan: The Step Before FBR Digital Invoicing (2026)' covers where those particulars live.
Who is actually at risk: the registered buyer
The 180-day rule hurts the buyer first. Only a registered buyer claims input tax, so only a registered buyer can lose it. A walk-in customer who pays cash for a fridge is not affected. The shop still needs a digital invoice for that sale, but Section 73 has nothing to take from someone who claims no input tax. 'Registered vs Unregistered Buyers on FBR Invoices: Registration Type, Further Tax and ATL Checks' explains the two buyer types.
For a registered buyer, the loss is real money. On a Rs 1,000,000 purchase at 18%, the input tax is Rs 180,000. Pay that supplier in cash, or pay by bank on day 200, and the Rs 180,000 cannot be subtracted from the tax the buyer owes. That is why a careful buyer refuses cash once the month's purchases pass Rs 50,000.
The seller's exposure is smaller. Money that does not land in the declared business account costs the seller its own input tax. Sub-section (4) also caps sales to unregistered buyers. That cap was once Rs 100 million a year or Rs 10 million a month; the Finance Act 2025 made it an amount FBR may prescribe.
The 180-day clock: how to count it
The clock starts on the invoice date, the date printed on the FBR digital invoice. It does not start from the delivery challan (the paper that travels with the goods) or from the day the buyer's accountant booked the bill. An invoice dated 17 September 2026 must be paid, through the bank, by 16 March 2027.
Part payments are fine, but each one should carry the invoice number in the bank narration (the note on the transfer). Every instalment should land inside the 180 days. The Act speaks of payment for the amount of the invoice, so treat the whole invoice as at risk, not just the late part.
The Rs 50,000 test is monthly, per supplier. Suppose a karyana store buys Rs 20,000 of goods from one distributor on the 3rd, the 12th and the 25th. Each bill is small, but the month's total is Rs 60,000. Every rupee of it now sits inside the bank rule. Counting bill by bill is the most common mistake here.
Cash, JazzCash and 'adjust it against what you owe me'
Cash is allowed only while the month's total with that supplier stays at Rs 50,000 or below. Above that line, cash is the one thing the section forbids. No receipt, stamp or signature fixes it.
Mobile wallets are the grey area. The Act names crossed cheques, drafts, pay orders, online transfers and credit cards. A transfer from a personal wallet to the seller's personal number is none of those. Unless the wallet is linked to the declared business bank account on both sides, do not rely on it.
Set-off, or 'adjust it against what you owe me', is common between a distributor and a shop that also supplies it. It counts only with the Commissioner's prior approval, and only when both sides charged and paid sales tax on their invoices. The section applies 'notwithstanding anything contained in this Act or any other law', so a contract with 90-day terms does not override it.
Set your invoice and your books up for credit sales
Declare your business bank account. Check that the account on your STRN registration is the one customers actually pay into, and update it in IRIS (FBR's online tax portal) if not. Print that account title and number on your invoice.
Post the invoice at delivery, with the true date. Give the buyer the IRN (Invoice Reference Number, the unique number FBR returns for every accepted invoice) and the QR code on the print. The buyer needs that number to claim input tax at all, as 'IRN and Input Tax Adjustment: Why Your Buyers Need FBR-Verified Invoices' explains.
Record every receipt against an invoice number. Keep the bank statement pages with the invoice for six years, the period set out in 'FBR Digital Invoicing Record-Keeping: Six-Year Retention, Digital Signatures & Audit Readiness (2026)'. Once a month, list unpaid invoices to registered buyers that are older than 150 days, and call those buyers first.
Digi Invoice keeps every posted invoice with its IRN, invoice date and buyer in one list, so seeing which credit invoices are ageing takes a minute. Buyer details are saved once and reused on every invoice. Create a free account, try it in the sandbox (FBR's free practice system, where nothing counts as real), and run your udhaar customers through it before the month closes.
Difficult words in this guide
Udhaar (credit sale) — the buyer takes the goods now and pays later. It changes when the money arrives, not when the invoice is due.
Input tax — the sales tax a registered business already paid on its purchases and subtracts from the tax it owes. Section 73 is about keeping this claim alive.
Tax period — one month under the Sales Tax Act 1990. The Rs 50,000 test is added up over a tax period, per supplier.
Business bank account — the account declared to FBR on Form STR-1 or through a change of particulars. Only this account counts under Section 73.
Crossed cheque — a cheque with two lines drawn across it, which a bank may only deposit into an account and never pay out as cash.