A business may spend months negotiating and finalising a deal with a supplier, but a single mistake on a purchase order (PO) can delay the transaction or even bring it to a halt. While purchase orders are a routine part of doing business, they are much more than just paperwork. They play an important role in managing procurement, controlling business spending, and maintaining strong supplier relationships.
In this article, we explain what a purchase order is, why it matters in the procurement process, and how businesses can improve purchase order management to make purchasing more efficient and reliable.
Key takeaways
- A purchase order is a formal document sent by a business to a supplier requesting goods or services
- It is identified by a unique PO number and holds information including a description of the goods requested, their quantity, price, delivery terms, dates, and so on
- Once approved by the supplier, a purchase order becomes a legally binding contract, protecting both parties' rights and minimising the risk of disputes
- There are 4 types of purchase orders – standard, blanket, contract, and planned purchase order – that are used depending on the nature of the procurement
- Purchase orders are more than mere documentation as they benefit businesses by creating clear expense records and audit trails, helping them manage inventory more efficiently and stay within budget, and strengthen relationships with suppliers
What is a purchase order and what purpose does it serve
A purchase order (PO) is a formal document a business sends to a supplier requesting goods or services at agreed-upon terms. It specifies the items being purchased, their quantity and price, the date and method of delivery, mode of payment, and so on.
When the supplier accepts the purchase order, it becomes a legally binding contract between the buyer and the seller, safeguarding their interests. Both parties are accountable to the terms and conditions laid out in the document. Changes to the transaction thereafter will require a formal amendment of the purchase order.
Apart from a legally binding agreement, a purchase order also serves as a formal record of a transaction. It helps businesses track supplier commitments, prevent duplicate or unauthorised purchases, forecast expenses, plan budgets more effectively, and maintain optimal inventory levels. It optimises spending by ensuring that every order is necessary, adequately assessed, and approved.
Furthermore, a purchase order creates a clear audit trail, which helps businesses make accurate reports and abide by tax and compliance requirements.
A purchase order is issued after the finalisation of talks with the vendor and before the delivery of goods. It is typically issued by a company's purchasing, procurement, or finance department.
Components of a purchase order
A purchase order contains the following details:
- Purchase order number, which is a unique identification code issued by the buyer. It can be used for order tracking and as a reference code for communication between the buyer and seller
- Buyer and seller details, including company names, addresses, contact details, contact persons, etc
- Detailed product description, quantity, unit price, and total price
- Payment terms, such as partial payment, due on receipt, Net 30 or Net 60 (payment terms indicating the number of days within which full payment is due). Acceptable payment methods and late fee details are also included
- Order date
- Delivery date and location
- Authorised signatures, confirming that the purchase order is authentic and approved
- Optional details such as shipping instructions, discounts, applicable taxes, etc
Types of purchase order
There are 4 types of purchase orders, each designed to address specific procurement needs:
Standard purchase order
This is the most common purchase order and is used when all the details of the transaction are clear from the start. A standard purchase order is typically used for one-time purchases.
Blanket purchase order
A blanket purchase order is commonly used for recurring purchases, such as consultancy services or regularly supplied goods. It allows businesses to procure an unspecified quantity of goods or services over a defined period under previously established pricing and contractual terms. A blanket purchase order eliminates the need to issue a new purchase order for every transaction, thus streamlining repeat orders, reducing administrative workload, and improving procurement efficiency. Furthermore, by locking in prices for a given period, it insulates businesses against price fluctuations.
Contract purchase order
A contract purchase order supports long-term supplier agreements. It establishes key terms – such as pricing, quality standards, contract duration, and delivery conditions – while leaving product quantities and delivery schedules flexible. For example, a manufacturer may issue a contract purchase order to a steel supplier, specifying the grade of steel required, pricing, and other contract details while leaving out the exact quantity to be supplied. Later, the manufacturer issues individual purchase orders for every order under the contract. By clearly defining contract terms and obligations upfront, contract purchase orders hold suppliers to a high level of accountability, minimise risk, and are particularly valuable in high-value buyer-supplier relationships.
Planned purchase order
A planned purchase order is used when a business anticipates future demand of goods or services but cannot confirm exact quantities, delivery schedules, or other specific details upfront. Commonly used by seasonal businesses (example, a beach-front resort preparing for the summer rush), planned purchase orders allow them to establish a framework for future transactions in advance while retaining flexibility over when and how much to order.
How purchase orders work
The purchase order process begins when a business identifies a need for goods or services and negotiates terms with a supplier. Once both parties agree on the terms, the buyer creates a purchase requisition – an internal document used to request approval for the purchase. This requisition must be reviewed and approved by the relevant authority.
After approval, the buyer creates a purchase order, including key details such as product descriptions, quantity, price, and expected delivery date. The purchase order is reviewed to ensure it complies with company policy and budget limits before being sent to the supplier. The supplier may accept or reject it. If accepted, it becomes a confirmed order.
The supplier then delivers the goods or services according to the agreed terms.
On delivery of the goods, the buyer verifies that they match the purchase order. At the same time, the supplier issues an invoice, which the buyer matches against the purchase order and delivery details before processing payment. Once payment is made, the transaction is concluded.
Purchase order vs invoice
It's easy to confuse purchase orders with invoices, but the two are different and serve different purposes. An invoice is issued by the seller after the terms and conditions of the purchase order have been fulfilled and the goods delivered. It is a request for payment from the buyer.
Like a purchase order, an invoice is a detailed official document whose key components include buyer and seller information, a detailed description of the purchased goods, pricing details including shipping costs and taxes, payment methods, order date and delivery date, shipping address, and PO number. It comes with an invoice date and a unique sequential invoice number that can be used for tracking and identification.
Purchase order vs purchase requisition
A purchase requisition is also frequently mistaken for a purchase order. A purchase requisition is an internal document created by a company employee or department requesting approval for the purchase of goods or services from a vendor. It is not sent to the vendor. Only after a purchase requisition has been approved can a purchase order be issued.
Purchase order vs sales order
A sales order, too, is different from a purchase order even if they sound similar. A sales order is created by the supplier after receiving the purchase order from the buyer. It is an internal document confirming the order and starting the process of fulfilling it. It is not sent to the buyer.
Key differences
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Purchase order best practices
Here's how business can prevent errors and inefficiencies from slipping into their purchase orders:
Ensure purchase orders are complete and accurate
Purchase orders contain a wide range of information that is essential for accurate order fulfilment. Every detail – from contact information and payment terms to individual line items – must be correct, complete, and clearly defined. Pay special attention to line items as they specify the exact goods or services being requested, including quantities, pricing, delivery requirements, etc. Complete and accurate purchase orders help prevent misunderstandings, delays, and other problems during the purchasing process.
Use a standardised format
A standardised purchase order template or format ensures that critical information is captured consistently and accurately, reducing the risk of errors and omissions. With a common structure, information is less likely to be misinterpreted, leading to more efficient order approval and fulfilment. Furthermore, standardised purchase orders make it easier to track transactions, verify if transactions have the necessary approvals, and maintain clear audit trails that enhance compliance and accountability.
Improve vendor management
Regularly evaluate supplier performance to ensure consistent quality and reliability. Purchase orders provide a clear record of transactions, making them a valuable tool for assessing suppliers based on product quality, on-time delivery, and pricing accuracy. They also help establish clear lines of communication by documenting expectations, agreed prices, and other terms. Monitoring vendor performance is essential for building a network of trusted, high-performing suppliers that reduces the risk of delay, overcharging, supply disruptions, and substandard goods or services.
Automate purchase order process
As businesses grow and procurement volumes increase, managing purchase orders and invoices manually becomes complex. Adopting electronic purchase orders and invoices and automating procurement workflows helps simplify operations and improve efficiency. Automation standardises data capture, streamlines approval workflows, and supports accurate record-keeping, which minimises errors and delays. Automation also makes it easier to check order status and reconcile invoices. By improving visibility into spending patterns, it helps businesses maintain tight budget control, be cost efficient, and make informed purchasing decisions. Furthermore, procurement technology offers valuable insights into trends and supplier performance, revealing areas for improvement.
Enhance accounts payable efficiency with Aspire
For Singapore businesses looking to automate and optimise their procurement and accounts payable processes, Aspire brings efficiency, control, and ease of use together in a single platform.
With Aspire, you can view all your accounts payable data on a single dashboard, giving you real-time visibility into spending and greater cost control. You can also set up multi-level approval workflows and custom spend controls for better budget management.
In addition, you can automate payments end to end, including scheduled bulk payments that make it easier to pay suppliers in multiple currencies. Our invoice management tool further simplifies invoice matching and reconciliation.
Conclusion
Purchase orders are a necessary part of the procurement process. By clearly documenting what a business orders, in what quantity, at what price, and under what terms, they help minimise buyer-seller disputes. When supported by the right technology and best practices, purchase orders do more than streamline the procurement process – they also help businesses improve efficiency, gain greater visibility into spending, and build trust with their suppliers.
FAQs
What is the difference between purchase order and invoice?
A purchase order is a formal document sent by a business to a supplier requesting goods or services at agreed-upon terms. After the seller accepts and approves the purchase order, it becomes a legally binding contract. An invoice, on the other hand, is a request for payment sent by the supplier to the business after the goods have been delivered.
Who creates a purchase order?
A purchase order is created by the buyer, more specifically their procurement or purchasing department.
What are the 4 types of purchase orders?
The 4 types of purchase orders are standard purchase order, blanket purchase order, contract purchase order, and planned purchase order.
What are some common purchase order mistakes?
Some common errors businesses make while issuing purchase orders include incomplete or inaccurate information, vague line item descriptions, missing approvals, not using a standardised purchase order format, and submitting duplicate purchase orders.
What is purchase order pricing?
Purchase order pricing includes the agreed-upon prices, rates, and other financial terms defined in a purchase order.
Can a purchase order be cancelled?
Yes, a purchase order can be cancelled. However, cancelling a purchase order after it has been approved by the supplier might result in a cancellation fee and additional charges (for example, for raw materials that have already been bought).
What is the PO number in Singapore?
The PO number or purchase order number is a unique tracking code generated by the buyer and printed on the purchase order.
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