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FBR invoice validator
Paste the details of a sales tax invoice and this checks it against every field Section 23 of the Sales Tax Act 1990 requires, plus the IRN, QR code and digital signature that FBR digital invoicing adds. It runs entirely in your browser — no upload, no sign-up, no data stored anywhere.
Nothing you type here leaves your browser.
Result
0/16 passedFill the fields on the left, or load the sample, and every check updates as you type.
- Supplier nameThe supplier's name must appear on the invoice.Section 23(1)(a)
- Supplier addressThe supplier's address is a required field, not optional.Section 23(1)(a)
- Supplier registration number (STRN)Missing. An invoice without the supplier's registration number is not a valid tax invoice.Section 23(1)(a)
- Buyer nameThe recipient's name must appear on the invoice.Section 23(1)(b)
- Buyer addressThe recipient's address is required.Section 23(1)(b)
- Buyer registration number (STRN)Missing. Without it your registered buyer cannot claim input tax — this becomes their problem and then yours.Section 23(1)(b)
- Serial numberEvery tax invoice must carry a unique serial number.Section 23(1)
- Date of issueThe date of supply must be shown.Section 23(1)(c)
- Description of goodsA description of the goods or services supplied is required — a bare line total is not enough.Section 23(1)(d)
- QuantityQuantity or volume must be shown against the description.Section 23(1)(d)
- Value excluding sales taxThe value of the supply before tax must be shown separately.Section 23(1)(e)
- Sales tax amountThe sales tax must be shown as its own amount, not folded into the total.Section 23(1)(f)
- Total including taxThe gross total payable must be shown.Section 23(1)(g)
- FBR Invoice Reference Number (IRN)Missing. The IRN is returned by FBR's Digital Invoicing API when the invoice is reported. Without one, this is not a valid FBR digital invoice — it is just a printed document.FBR Digital Invoicing
- FBR QR code printedThe FBR QR code must be printed on the invoice so it can be verified by scanning.FBR Digital Invoicing
- Digital signatureInvoices under the digital invoicing mandate carry a digital signature.FBR Digital Invoicing
This tool checks the fields an invoice must carry. It is a drafting aid, not tax advice, and it cannot confirm that an invoice was actually accepted by FBR — only your integration can do that.
Field reference
What a valid sales tax invoice must carry
The full list, with where each requirement comes from.
| Field | Requirement | Note |
|---|---|---|
| Supplier name, address, STRN | Section 23(1)(a) | Identifies who made the supply. The STRN is normally 13 digits. |
| Buyer name, address, STRN | Section 23(1)(b) | Without the buyer's STRN a registered customer cannot recover input tax. |
| Buyer NTN or CNIC | Where the buyer is unregistered | Required where a manufacturer or importer supplies an unregistered distributor. |
| Serial number | Section 23(1) | Unique and sequential. Gaps in the series are among the first things a review looks for. |
| Date of issue | Section 23(1)(c) | The date of supply, and the date of issue where they differ. |
| Description and quantity | Section 23(1)(d) | A line total with no description is not sufficient. |
| Value excluding sales tax | Section 23(1)(e) | Shown separately from the tax. |
| Sales tax amount | Section 23(1)(f) | Must be its own figure, never folded into the total. |
| Total including tax | Section 23(1)(g) | The gross amount payable. |
| Invoice Reference Number (IRN) | FBR digital invoicing | Returned by FBR's API when reported. About 22 characters. |
| FBR QR code | FBR digital invoicing | Printed on the invoice so it can be verified by scanning. |
| Digital signature | FBR digital invoicing | Carried by invoices issued under the mandate. |
Why it matters
The cost of a missing field
Your buyer loses their input tax
A registered buyer cannot claim input tax on an invoice missing their registration number. The invoice becomes their cost — and then a conversation you have to have.
You have 72 hours to fix it
Sales Tax General Order No. 01 of 2026 allows edits or cancellation through the FBR system for 72 hours. After that, a correction needs Commissioner Inland Revenue approval.
Non-integration is expensive
Penalties for failing to integrate with FBR digital invoicing start at Rs 500,000 under Section 33 of the Sales Tax Act 1990, and enforcement began in January 2026.
If you are checking invoices by hand, the underlying problem is usually that the invoice is created somewhere that does not know the rules. Read the full Section 23 guide with a free template, or see how FBR digital invoicing works inside AmalERP so the fields are never missing in the first place.
FAQ
Frequently asked questions
What makes a sales tax invoice valid in Pakistan?
Under Section 23 of the Sales Tax Act 1990 it must carry the supplier's name, address and registration number; the buyer's name, address and registration number; a unique serial number; the date; a description and quantity of what was supplied; the value excluding sales tax; the sales tax amount shown separately; and the total including tax. If you are under FBR digital invoicing, it must also carry an Invoice Reference Number (IRN), an FBR QR code and a digital signature.
Is an invoice without an IRN valid?
Not as an FBR digital invoice. The IRN is returned by FBR's Digital Invoicing API when the invoice is reported, and it is roughly 22 characters. A document printed without one has not been reported, so it is a printed page rather than a reported tax invoice — whatever else is on it.
What happens if a field is missing?
The most immediate consequence is commercial rather than legal: a registered buyer cannot claim input tax on an invoice missing their registration number, so an incomplete invoice becomes their cost and then your problem. Separately, failure to integrate with FBR digital invoicing carries penalties starting at Rs 500,000 under Section 33 of the Sales Tax Act 1990, with enforcement having begun in January 2026.
Can I correct an invoice after issuing it?
Sales Tax General Order No. 01 of 2026 provides a 72-hour window to edit or cancel a reported invoice through the FBR system. After that window a change needs approval from the Commissioner Inland Revenue, which is why it pays to catch a missing field before the invoice goes out rather than at month end.
What if my internet is down when I need to issue an invoice?
FBR's published FAQs allow invoices to be issued in offline mode during an internet or power outage, provided they are uploaded to the FBR system within 24 hours of connectivity being restored. The 24 hours runs from the moment you are back online, not from when the outage started.
Does this tool send my invoice data anywhere?
No. Every check runs in your browser using JavaScript on the page. Nothing is uploaded, stored or logged, and the tool works with your network disconnected. We built it that way because nobody should have to hand a real tax invoice to a software vendor to find out what is missing from it.
Is this tax advice?
No. It checks whether an invoice carries the fields the rules require, which is a drafting aid. It cannot tell you whether a supply is taxable, what rate applies, or whether FBR accepted a particular invoice — only your integration and your tax adviser can answer those.
Stop checking invoices by hand
AmalERP reports every sale to FBR as you raise it, and the IRN and QR come back on the invoice automatically. From 2,500 PKR/month with a 7-day free trial.
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