Purchase order format: every field, a GST-ready sample, and PO vs quotation vs invoice

On a fit-out or construction job, materials are where money goes fastest: gypsum, tiles, ply and wire, ordered from a dozen vendors, often by a site engineer on a phone call. The purchase order (PO) turns those calls into a record. The BOQ is what the job is priced on, and the RA bill is how you get paid. The PO is how you spend against the BOQ, and it’s where cost overruns either get caught or slip through.

What a purchase order is (and isn’t)

A purchase order is the buyer’s written order to a vendor. You issue it after you’ve compared quotations and picked one, and it fixes the item, quantity, rate, delivery and payment terms.

• It’s your order on record. A vendor can accept it by signing it back, or simply by acting on it: section 8 of the Indian Contract Act treats carrying out the conditions of a proposal as accepting it. So write down the terms you mean to hold the vendor to.
• It isn’t a GST document. GST law prescribes what the vendor’s tax invoice must contain (Rule 46 of the CGST Rules, 2017). It also prescribes documents such as the bill of supply, receipt voucher, and credit and debit notes. A PO isn’t one of them, and there’s no government PO format.

The second point is the useful one. The vendor’s invoice must carry certain fields, so build your PO with the same ones. When the invoice arrives, you check it against the PO line by line instead of eyeballing a total.

The purchase order format: every field

• Buyer header: your business name, address and GSTIN.
• “Purchase Order,” a PO number and the date. Use one numbering series with the financial year in it (e.g. ABC/PO/26-27/014).
• Vendor details: name, address and GSTIN, from the registration the vendor will invoice under.
• Ship-to address: on a project, this is the site, with a site contact. It decides where the goods go, and often which tax applies.
• Reference: the vendor’s quotation number (where your rates come from) and the job or BOQ reference.
• Line items: description and specification, HSN (goods) or SAC (services) code, quantity, unit, rate, and taxable value (qty × rate). Use the GST unit codes, such as NOS and SQM, because the invoice must show quantity with its unit.
• Tax and total: CGST + SGST for a supply within the state, or IGST for one across states, each as a separate line, then the grand total.
• Delivery terms: date, place, unloading, and who generates the e-way bill.
• Payment terms: the credit period, any advance, and what starts the clock (usually receipt of the goods plus a correct tax invoice).
• Conditions and signature: brand or quality specification, how short deliveries are handled, “quote this PO number on your invoice,” and an authorised signatory.

Subcontracts work differently. A fit-out subcontract that supplies both material and labour is a works contract, which GST treats as a supply of services. It’s usually raised as a work order with a SAC code (construction services fall under heading 9954) rather than the HSN codes of the materials.

A sample purchase order that ties out

In this example, a Bengaluru fit-out firm orders materials for an office project from a Bengaluru supplier. Both are in the same state, so the tax is CGST + SGST. All four items are in the 18% slab (9% CGST + 9% SGST) of the goods rate notification in force since 22 September 2025 (No. 9/2025-Central Tax (Rate)); check the current rate before you issue a real PO. The item rates are illustrative, not market quotes.

ABC Interiors Pvt Ltd · Bengaluru · GSTIN 29ABCDE1234F1Z5

PURCHASE ORDER: No. ABC/PO/26-27/014 · Date: 21 Oct 2026 To: XYZ Building Supplies, Bengaluru · GSTIN 29PQRST5678K1Z2 Ship to: Project site, 3rd floor, Whitefield, Bengaluru (site engineer: +91 9xxxx xxxxx) Ref: Vendor quotation XYZ/Q/412 dated 17 Oct 2026

#	Item	HSN	Qty	Unit	Rate (₹)	Taxable value (₹)
1	Gypsum board 12.5 mm, 1830×1220	6809	120	NOS	480	57,600
2	Vitrified tile 600×600 mm	6907	180	SQM	720	1,29,600
3	Plywood 18 mm BWP, 2440×1220	4412	40	NOS	2,650	1,06,000
4	FR copper wire 2.5 sq mm, 90 m coil	8544	25	NOS	1,980	49,500
					Taxable total	3,42,700
					CGST @ 9%	30,843
					SGST @ 9%	30,843
					PO total	4,04,386

Delivery: to site by 31 Oct 2026, unloading by vendor; vendor to generate the e-way bill · Payment: 30 days from receipt of goods and a correct tax invoice · Quote this PO number on the invoice and delivery challan. For ABC Interiors Pvt Ltd, Authorised Signatory

This sample leads to two checks. First, the consignment is worth more than ₹50,000, the Rule 138 threshold, so it will generally need an e-way bill before it moves, and the PO says who raises it. Second, the vendor’s invoice should come back with the same four lines, HSN codes and rates. If anything differs, query it before you pay.

PO vs quotation vs invoice

	Quotation	Purchase order	Tax invoice
Issued by	Vendor	Buyer	Vendor
When	While you’re deciding	When you decide to buy	At or before dispatch of goods (services: within 30 days of supply)
What it says	”Here’s my price, valid till…"	"Supply this, at this rate, on these terms"	"Supplied: here’s the bill and the GST”
GST role	None	None	Mandatory fields (Rule 46); needed to claim input tax credit

The usual order is quotation → PO → dispatch with the tax invoice (and e-way bill) → delivery → payment. For goods, the invoice is due at or before dispatch, so it normally travels with the material. If the vendor wants an advance, a proforma invoice can come after the PO. Like the quotation and the PO, it doesn’t support an input tax credit claim.

The GST rules that shape a PO

• CGST + SGST, or IGST. Which one applies depends on two locations: the vendor’s and the place of supply. If both are in the same state, it’s CGST + SGST. If they’re in different states, it’s IGST at the two rates combined (for the sample’s items, 18% IGST instead of 9% CGST + 9% SGST). For goods that are moved, the place of supply is generally where the movement ends for delivery. For services directly related to a building, such as interior decoration, architecture or construction work, it’s where the building is. If your site and your GST registration are in different states, ask your accountant which GSTIN the PO and invoice should carry.
• HSN digits. A vendor whose turnover was above ₹5 crore in the previous financial year must show 6-digit HSN/SAC codes on invoices. Up to ₹5 crore, 4 digits are required on B2B invoices. Put codes on the PO at the same level the vendor invoices at.
• ITC needs the invoice and the goods. Among other conditions, you can claim input tax credit only if you hold the vendor’s tax invoice (or debit note) and have actually received the goods or services. The PO lets you check that invoice, and a goods-receipt record against the PO shows what actually arrived.
• E-way bill above ₹50,000. Under Rule 138, a consignment worth more than ₹50,000 generally needs an e-way bill before it moves. For movement within a state, some states set a higher limit or exempt certain areas, so check your state’s rule.
• MSME payment terms. Some vendors are micro or small enterprises with an Udyam registration that isn’t trading-only. For them, Section 15 of the MSMED Act caps an agreed credit period at 45 days from the day the goods or services are accepted (or deemed accepted), not from the invoice date, or 15 days if nothing is agreed in writing, and late payments carry interest under Section 16. A “90 days” clause doesn’t change that.

Common PO mistakes on site

1. Ordering on WhatsApp and documenting later. If the PO is raised after the invoice, or never, the invoice sets the rate, not you.
2. “Rate as discussed.” If a line doesn’t have both a rate and a unit, every invoice becomes a negotiation. A tile rate per box and a rate per square metre are very different numbers.
3. Amending by phone. Quantities change on site, and that’s normal. Issue a revised PO (ABC/PO/26-27/014-R1) so the record matches what you’ll be billed.
4. No receipt check. If nobody records what actually arrived against the PO, short deliveries get paid in full.
5. POs not tied to the BOQ. Each PO looks fine on its own. But if they aren’t linked to BOQ lines, nobody sees that the gypsum line has already used 110% of its estimate until the project closes.

Tying POs to the BOQ

That last mistake is the expensive one, and it comes from how the records are kept. The BOQ is in Excel, the POs are in a PDF folder or a WhatsApp chat, and the invoices are somewhere else. So nobody compares procurement cost with the estimate while there’s still time to act.

Boqos closes that gap for interior fit-out and design-build firms. It’s AI-native quote-to-cash software: from scope to BOQ, proposal to e-approval, and variation to invoice, without Excel. Its procurement tracking links purchase orders to BOQ line items, so landed costs are tracked against the estimate before you’re overrun. Every variation is priced, client-approved and added to the contract before the work starts.

You don’t need software for your first PO; the format above works in a spreadsheet. But once three sites are ordering from a dozen vendors at the same time, checking every PO against the BOQ by hand is the step that gets skipped.

The short version

A purchase order is the buyer’s written order. It carries a PO number and date, both GSTINs, the site address, itemised lines with HSN, quantity, unit and rate, the tax split, delivery and payment terms, and a signature. GST prescribes no PO format, but the vendor’s invoice has mandatory fields, so mirror them and check the invoice line by line. Watch the place of supply, the e-way bill above ₹50,000 and the 45-day limit for micro and small vendors. And tie every PO to a BOQ line.