Guide

Five Things Every Purchase Order Should Include (But Most Don't)

Zigaflow28 June 20264 min read

Purchase Orders12 open

Midocean UK - Polo shirtsPO-0237In Production

PF Concept - Tote bagsPO-0235Part Received

LALTEX Group - Water bottlesPO-0233Awaiting PO

Ralawise - HoodiesPO-0231Received

Midocean UK - LanyardsPO-0229Awaiting PO

A poorly written purchase order creates as many problems as it prevents. This checklist covers five fields most SMBs consistently overlook - from delivery dates to job references - and explains why each one matters when something goes wrong.

A purchase order is meant to protect you. It is your formal record of what you ordered, from whom, at what price, and when it should arrive. But a poorly written PO does the opposite: it creates ambiguity that costs time and money the moment something goes wrong. For small to medium-sized businesses running multiple jobs at once, the gap between a functional purchase order and a vague one is the difference between a clean supplier relationship and an invoice dispute that takes three phone calls to resolve. These five elements are the difference.

1. A Delivery Date - Not "ASAP"

"As soon as possible" is not a delivery date. Suppliers interpret it in their own interest, which means you have no standing to push back when goods arrive a week late - after the job needed them. Every purchase order needs a specific date, and for project-based businesses it should tie directly to when the job needs those materials on site.

If the delivery date is critical, say so on the PO. "Required on site by 14 July 2026 - please confirm by return." That one line changes the nature of your communication from a request to a commitment. It also gives you a clear reference point if the delivery misses.

Vague delivery instructions

If your PO says "ASAP" or leaves the date blank, you lose the right to dispute late delivery without an argument. State when you need goods on site, not when you would like them to leave the supplier's warehouse.

2. Itemized Line Details That Leave No Room for Interpretation

"Miscellaneous parts" and "supply of materials" are descriptions that generate invoice disputes. If the supplier invoices for something unexpected and your PO description is vague, you have very little to push back with. Analysis from GEP found that vague line items are among the most common root causes of supplier invoice mismatches - leading to delays, over-payments, and return headaches.

Every line on a purchase order should include the item description, quantity, unit of measure, and agreed unit price. For more complex orders - branded goods, made-to-spec items, or materials with specific grades - add a product code or specification reference. It takes an extra 30 seconds to write and saves significant time later.

3. A Job Reference

This is the most frequently overlooked detail in smaller businesses. If a purchase order does not reference the job, project, or customer order it relates to, your costs do not flow to the right place when the invoice arrives. Finance chases the number, someone works backwards to figure out which job the cost belongs to, and the reconciliation takes far longer than it should.

A single job reference field on every PO - your internal job number, project name, or customer order reference - prevents this entirely. It also makes supplier disputes much easier to resolve, because you can immediately trace the order to its context.

Cross-reference to invoices

When your POs carry job references, matching supplier invoices to the right cost center is a quick check rather than an investigation. This matters most when you have several active jobs running simultaneously with the same supplier.

4. Payment Terms - Written Down, Not Assumed

The price on a purchase order is only half of the financial agreement. The other half is when you are expected to pay and what the terms are. If your PO does not state payment terms - 30 days net, for example - the supplier can apply their own standard terms, which may be shorter than you expect or different from what you agreed verbally.

Write payment terms clearly on every PO. If you have a trade account with a supplier, reference that account number too. It protects you from unexpected payment demands and gives you a clear record if terms are disputed later.

5. An Authorizing Name and Contact

Who raised this PO? Who approved it? Who should the supplier call if there is a problem with the delivery?

For businesses where the owner is not always the one raising purchase orders, an authorization trail matters. It tells the supplier that the order has been properly approved - not just sent. It gives them a named contact to reach if there is a question, which reduces the chances of delivery confusion or unannounced substitutions arriving on site.

Keep it simple: the name of the person who raised the PO and a direct phone number or email. That is enough.

These five elements add a few minutes to writing any purchase order. What they do in return is reduce the number of supplier conversations that begin with "that is not what we agreed." A clear PO is a form of insurance - it costs nothing to get right and is expensive to have wrong.

Zigaflow's purchase orders feature helps project-based businesses raise and track POs against specific jobs, keeping supplier costs linked to the right order from the moment the PO is issued.

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