Purchase Order
What is Purchase Order?
A purchase order (PO) is a document a buyer issues to a supplier to authorize a purchase, specifying the items or services, quantities, prices and terms. Once accepted, it becomes a binding commitment.
Updated November 2026 · 5 min read
A purchase order, usually called a PO, is how an organization formally tells a supplier what it wants to buy. It lists what is being purchased, how many, at what price, when it should be delivered and under what terms. When the supplier accepts the purchase order, it typically becomes a legally binding agreement. The PO number then follows the transaction through delivery, invoicing and payment, linking every record of the purchase.
Purchase orders are a basic control in most organizations' finance processes. They make sure purchases are approved by the right people before money is committed, give finance a record of what has been ordered and allow invoices to be checked against what was agreed. For IT financial management, purchase orders provide early visibility of technology commitments and support accurate budgeting, accruals and cost tracking.
Definition of Purchase Order
A purchase order is a commercial document issued by a buyer to a seller, indicating the types, quantities and agreed prices of products or services. It authorizes the supplier to deliver, and it records the buyer's commitment to pay once delivery conditions are met.
A PO typically includes a unique PO number, buyer and supplier details, item descriptions, quantities, unit prices, total amount, delivery dates and locations, payment terms and references to any governing contract, such as a master services agreement (MSA).
Types of Purchase Orders
A standard purchase order covers a one-time purchase of specific items at specific prices, such as a batch of laptops. A blanket purchase order covers repeated purchases from a supplier over a period, up to a set amount, which is useful for recurring services or consumables.
A contract purchase order references an existing agreement and sets out terms without specifying individual items, while a planned purchase order states expected purchases and delivery dates in advance, with releases issued as needed.
Blanket purchase orders are common for technology services, such as cloud consumption or contractor hours, where the exact amount is not known in advance. They set a ceiling for spending and allow invoices to be matched against it throughout the period.
Purchase Orders and Invoices
A purchase order is created by the buyer before goods or services are delivered. An invoice is created by the supplier after delivery, requesting payment. The two are matched to confirm that the buyer is paying for what it ordered.
Many organizations use three-way matching, comparing the purchase order, the goods receipt or service confirmation and the invoice. Payment is released only when all three agree, which prevents overpayment, duplicate payment and payment for items never received.
Importance of Purchase Orders in IT Financial Management
Purchase orders provide control and visibility over spending. For technology, where purchases range from small software subscriptions to multi-million-dollar hardware and service contracts, they are a key part of financial discipline.
They also provide data that IT finance teams use for planning, forecasting and reporting.
In many organizations, a purchase order is also the point at which the cost is classified to the right account, cost center and project, which determines how it will appear in later reports.
Control and Approval
Requiring a purchase order before buying ensures that spending is approved by the right people and fits within budget. Approval workflows route POs to budget owners, IT leaders and finance based on amount and category, so larger commitments receive more scrutiny.
Purchases made without POs, often called maverick or off-contract spending, bypass these controls and often miss negotiated discounts. In technology, this commonly happens with SaaS bought on corporate cards, which is one reason shadow IT is difficult to manage.
Visibility and Accruals
Open purchase orders show committed spending that has not yet been invoiced. This helps IT finance teams forecast costs, track budget consumption and identify commitments before they appear in the general ledger.
At month-end, delivered goods or services with open POs but no invoice can be accrued, keeping costs in the right period. Purchase order data is therefore an important input to accrual accounting for technology costs.
How to Use Purchase Orders Effectively
Using purchase orders effectively requires clear policies, efficient workflows and accurate coding of each order.
The process should be quick enough that people use it, since slow approvals encourage workarounds. Purchase orders are a central step in the procure-to-pay process, which connects requisition, ordering, receipt, invoicing and payment.
Policies and Thresholds
Organizations define when purchase orders are required, often for all purchases above a set amount, along with approval levels and exceptions. Low-value purchases may be handled through cards or simplified processes to avoid unnecessary administration.
Policies should cover technology-specific cases, such as SaaS subscriptions, cloud commitments and renewals, which can be overlooked if treated as routine. Requiring POs for renewals gives an opportunity to review usage and terms before committing again. Without that checkpoint, many renewals proceed automatically and are only noticed when the invoice arrives.
Coding and Data Quality
Each purchase order should be coded to the correct account, cost center, project and, where relevant, application or service. Accurate coding at the start makes reporting and cost allocation much easier later. Correcting miscoded transactions after the fact takes far more effort and is often incomplete.
Consistent supplier names, item descriptions and categories also improve the quality of spend analysis, allowing organizations to see how much they spend with each supplier and in each category.
Examples of Purchase Orders in IT Financial Management
The examples below show how purchase orders support control and visibility for technology spending.
Both use illustrative figures for a mid-sized company.
In each, the purchase order provided information that helped prevent a problem.
Catching an Invoice Error
A company issues a purchase order for 200 laptops at $1,350 each, a total of $270,000. The supplier delivers 200 laptops but invoices for 220 at $1,400 each, a total of $308,000.
Three-way matching flags the differences in quantity and price. The invoice is returned for correction, preventing an overpayment of $38,000. Without the purchase order, the accounts payable team would have had no agreed figures to check the invoice against.
Forecasting From Open Purchase Orders
At the end of the third quarter, an IT finance team reviews open purchase orders and finds $2.4 million of hardware and services ordered but not yet delivered or invoiced, mostly for a network upgrade.
Including these commitments in the forecast shows that the IT budget will be fully used by year-end. The team defers two discretionary purchases to avoid an overspend that would not have been visible from invoices alone.
It also accrues $600,000 for equipment already delivered but not yet invoiced, so that third-quarter costs reflect what was actually received. Without the open purchase order data, both the forecast and the quarter's reported costs would have been understated.
Conclusion
A purchase order is a document a buyer issues to authorize a purchase, specifying items, quantities, prices and terms. Once accepted, it becomes a binding commitment and is matched with receipts and invoices before payment.
In IT financial management, purchase orders provide control over technology spending, early visibility of commitments and data for accruals, forecasting and spend analysis. Clear policies, efficient approvals and accurate coding help organizations use purchase orders to keep technology spending under control.
Related terms
Master Services Agreement (MSA)
A master services agreement (MSA) is a contract that sets the general terms of a customer-vendor relationship, so future work can be ordered through shorter statements of work.
General Ledger
A general ledger is the master record of all financial transactions in an organization, organized by account. It is the source for financial statements and the starting point for analyzing costs.
Accrual Accounting
Accrual accounting is a method that records revenue when it is earned and expenses when they are incurred, regardless of when cash changes hands. It is required under US GAAP and IFRS.
Procure-to-Pay
Procure-to-pay (P2P) is the end-to-end process of buying goods and services, from identifying a need and requesting it through ordering, receiving, invoicing and paying the supplier.