What is the time limit for issuing a GST invoice?

For goods, before or at the time of removal (or delivery). For services, within 30 days of the date of supply, or 45 days for banks, insurers, financial institutions and NBFCs.

Is a signature mandatory on a GST invoice?

A signature or digital signature of the supplier or authorised person is required, but not on an electronic invoice issued in accordance with the Information Technology Act, 2000.

How many copies of a GST invoice are required?

Three for goods (recipient, transporter, supplier) and two for services (recipient, supplier). These copy rules don't apply to e-invoices reported to the IRP.

Can I issue one invoice for many small sales?

Yes, for sales below ₹200 each to unregistered buyers who don't ask for an invoice, you can issue one consolidated invoice at the end of the day.

When is a bill of supply issued instead of a tax invoice?

When the supply is exempt, or when the supplier is a composition dealer. A bill of supply doesn't show GST.

Do I need a GST invoice for free samples?

Usually no. Circular 92/11/2019-GST clarifies that samples supplied free of cost, without consideration, are not a supply (except Schedule I cases), so no tax invoice and no output GST. You must reverse ITC under Section 17(5)(h) and typically move the goods on a delivery challan.

Is ITC available on free samples under GST?

Under current law, no: Section 17(5)(h) blocks ITC on goods disposed of as gifts or free samples, and Circular 92 confirms that. The 57th GST Council (8 Oct 2026) recommended removing that block; until a CBIC notification amends the Act, reverse the credit.

GST Invoice Rules: Free Samples & Contents

GST law is specific about invoices: what they must contain, when you must issue them, how many copies to make and which document to use for which transaction. Get these right and your buyer's input tax credit, your returns and your e-way bills all fall into place. This guide covers the rules for small and mid-sized businesses. For a ready layout, see our GST invoice format.

Who must issue a tax invoice?

Every GST-registered person making a taxable supply issues a tax invoice (Section 31). Composition dealers and businesses supplying only exempt goods or services issue a bill of supply instead, without charging GST. Unregistered businesses can't charge GST at all.

Time limits for issuing invoices

Supply	Issue the invoice
Goods	Before or at the time of removal of goods for supply (or delivery, where goods aren't removed)
Services	Within 30 days of the date of supply (45 days for banks, insurers, financial institutions and NBFCs) (Rule 47)
Continuous supply of goods	Before or at the time each statement is issued or payment is received

What a tax invoice must contain

Supplier's name, address and GSTIN
A consecutive serial number of up to 16 characters, unique for the financial year (letters, digits, hyphen and slash allowed)
Date of issue
Recipient's name, address and GSTIN if registered; for unregistered buyers, name, delivery address and state when the value is ₹50,000 or more
HSN code (goods) or SAC (services), with 4 or 6 digits depending on turnover
Description, quantity and unit
Total value, taxable value after discounts, rate and amount of CGST, SGST/UTGST, IGST and cess
Place of supply with the state name, for inter-state supplies
Delivery address, if different from the place of supply
Whether tax is payable under reverse charge
Signature or digital signature of the supplier or authorised person (not needed on an electronic invoice issued under the IT Act)

Businesses above the e-invoicing limit must also show the IRN and QR code; see the e-invoice limit.

How many copies?

Supply	Copies (Rule 48)
Goods	Triplicate: original for the recipient, duplicate for the transporter, triplicate for the supplier
Services	Duplicate: original for the recipient, duplicate for the supplier

For e-invoices reported to the IRP, the triplicate and duplicate copy requirements don't apply (Rule 48(6)).

Small retail sales

If a sale is below ₹200, the buyer is unregistered and doesn't ask for an invoice, you may issue one consolidated invoice for all such sales at the end of the day (proviso to Rule 46). Most shops still bill every sale, which keeps stock and cash accurate.

Documents under GST
Document	When it's used	Rule
Tax invoice	Taxable supply by a registered person	Section 31, Rule 46
Bill of supply	Exempt supplies, or any supply by a composition dealer	Rule 49
Invoice-cum-bill of supply	One document for taxable and exempt supplies to an unregistered buyer	Rule 46A
Receipt voucher	Advance received for a supply	Rule 50
Refund voucher	Advance refunded when no supply is made	Rule 51
Self-invoice and payment voucher	Purchases from unregistered suppliers on which you pay tax under reverse charge (self invoice format)	Section 31(3)(f), Rules 47A, 52
Credit note / debit note	Value or tax reduced (returns, discounts) or increased after the invoice	Section 34, Rule 53
Delivery challan	Goods moved without a sale: job work, stock transfer, on approval	Rule 55

Penalties for invoice mistakes

Supplying without an invoice, or issuing an incorrect or false invoice, can attract a penalty of ₹10,000 or the tax involved, whichever is higher (Section 122). Minor errors such as a typo are usually corrected with a credit or debit note, or in a later return, but repeated errors cost your buyers input tax credit and cost you time.

Invoice for free samples under GST

Shops and manufacturers often give free samples to doctors, dealers or customers. People then search for an “invoice for free samples under GST”. The short answer from CBIC Circular 92/11/2019-GST (7 March 2019) is:

No tax invoice is needed for a true free sample. Goods given free of cost, without any consideration, are not a “supply” under Section 7 (unless the activity falls under Schedule I, for example supplies to related persons). So you generally do not charge GST and you do not raise a tax invoice for that free sample.
Reverse the input tax credit on inputs, input services and capital goods used for those free samples or gifts, under Section 17(5)(h). Record the write-off in your stock register (Rule 56 also lists gifts and free samples).
Use a delivery challan to move the goods when samples leave your premises without a sale (Rule 55). Our delivery challan format follows those fields. A proforma invoice can state commercial terms, but it is not a tax invoice.
Buy one, get one free is different: Circular 92 treats it as two (or more) supplies for one price, not a free gift. Tax and ITC follow the normal rules for that composite or mixed supply.
57th GST Council (8 Oct 2026): the Council recommended amending Section 17(5) so ITC is no longer blocked on free samples (and on goods destroyed or written off on expiry as required by law). That is a recommendation only. Until CBIC notifies the change, Section 17(5)(h) and Circular 92 still apply. Source: PIB press release PRID 2320934.

For the editable tax-invoice layout when you are making a sale, use the GST invoice format or the free GST invoice generator.

A quick invoice checklist

Is the buyer's GSTIN correct and active, and does the state match the place of supply?
Is the invoice number next in the series for this financial year?
Does every item have the right HSN/SAC and current GST rate?
CGST + SGST for intra-state, IGST for inter-state?
Reverse charge marked where it applies?
For goods over ₹50,000, is an e-way bill needed? Check with the e-way bill checker.

How VelBooks helps

VelBooks GST billing software fills in your details, numbers invoices consecutively, applies the HSN code and rate saved on each item and splits tax by place of supply, so every invoice meets these rules. New to the idea? Read what GST billing software is. Need a one-off invoice? Try the free GST invoice generator.

Sources

This article is general information, not legal or tax advice. Rules change; check the official sources above or consult your tax adviser.

GST Invoice Rules: Time Limits, Free Samples, Contents and Document Types