What's Planergy?

Modern Spend Management and Accounts Payable software.

Helping organizations spend smarter and more efficiently by automating purchasing and invoice processing.

We saved more than $1 million on our spend in the first year and just recently identified an opportunity to save about $10,000 every month on recurring expenses with Planergy.

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Cristian Maradiaga

King Ocean

Download a free copy of "Indirect Spend Guide", to learn:

  • Where the best opportunities for savings are in indirect spend.
  • How to gain visibility and control of your indirect spend.
  • How to report and analyze indirect spend to identify savings opportunities.
  • How strategic sourcing, cost management, and cost avoidance strategies can be applied to indirect spend.

Difference Between Purchase Order and Invoice

Purchase order vs. invoices - what’s the difference


  • Purchase orders are an official document that businesses use to place an order with a vendor
  • Invoices are official documents that vendors send to buyers to request payment for goods and services
  • Both documents contain key information, such as quantity, price, item number and description, payment terms, and a unique identifying number
  • Purchase orders come before invoices in the procurement process
  • Invoices can be sent without a purchase order in certain situations, but usually are sent after a purchase order is received
  • Procurement software can streamline and automate purchase order and invoice processing

Purchase orders and invoices are documents that nearly every finance department deals with on a daily basis. So, what are these two documents, and why are they such an important part of the procurement process?

What Is a Purchase Order?

A purchase order (PO) is a legal document that officially confirms an order. It’s sent from a purchaser to a vendor to authorize a purchase. A PO contains all the information the vendor needs to fulfill the order, including the product or service, description, quantity, and delivery information.

It also contains the payment terms for the purchase, such as ‘ net 30’, which means that the buyer will pay the seller within 30 days of delivery. Because a purchase order is legally binding, vendors are able to fulfill orders before they receive payment. It is essentially a legal guarantee that they will be paid.

A purchase order looks like this:

Purchase Order Example

The standard format for a purchase order will usually include a number of sections:

  1. Header
  2. Supplier information
  3. Delivery information
  4. Item information
  5. Order total
  6. Terms and conditions

Purchase Order Format

What Are the Benefits of Using Purchase Orders?

Purchase orders are the standard for almost all businesses-to-business purchases because of the benefits they provide for procurement and accounts payable teams. Some of those benefits include:

  • Improved financial accuracy and record keeping
  • The ability to ensure payments match orders through 2-way matching and 3-way matching
  • A legal basis for clear payment and delivery terms
  • Increased ability to control budgets as orders must go through a purchase requisition process and funds must be allocated to specific POs

What Is an Invoice?

An invoice is a document that requests payment for a purchase made through a purchase order. It’s sent from the vendor that the buyer sent a PO to, and should match the details on the PO such as quantity, price, and totals. The invoice should also display the PO number from the order it’s for.

In some cases, invoices can be sent without a purchase order. This may happen when an order is placed with a credit card over over the phone or through an eCommerce website. This is more common for small purchases or even for consumer payments. However, for most business-to-business purchases, a PO precedes the invoice.

Invoices should match the payment terms that the vendor agreed to. For example, if the buyer request 30 days for their payment terms, the invoice should state that the payment due date is in 30 days.

It also must include an accurate billing address and contact information, and any other information that the buyer needs to complete the payment. For example, if the vendor would like a check, it should specify who to make it out to. If they want a wire transfer, the account and routing numbers should be on the invoice.

An invoice could look like this:

Invoice Example

What Are the Benefits of Using Invoices?

Just like purchase orders, invoices are the industry standard for accepting business-to-business payment requests because of the many benefits they provide. When a buyer sends a purchase order, an invoice is almost always what the vendor sends for payment.

Other than being the industry standard, the benefits of using an invoice include:

  1. An easy way to track expected payments and cash flow
  2. A paper trail that proves payment was requested
  3. Increased billing accuracy and clear terms for payments
  4. A faster way to get paid when paired with an eProcurement system like Planergy

Benefits of Using Invoices

What Is the Difference Between a Purchase Order and an Invoice?

The difference between a purchase order and an invoice is that a purchase order confirms that an order has been placed while an invoice requests payment for an order. A purchase order comes before the invoice, and the invoice is the supplier’s response to the purchase order—along with the goods and services delivered.

Differences Between Purchase Orders and Invoices

DocumentPurchase OrderInvoice
What it isOfficial confirmation of an orderRequest for payment for an order
Who receives itVendorPurchaser
When it is sentBefore the order is fulfilledAfter the order is fulfilled
What it contains
  • Date of purchase
  • Company names
  • Item quantities and descriptions
  • Price
  • Payment information
  • Billing address
  • Purchase order number
  • Shipping address
  • Terms of payment
  • Expected delivery date
Same information as on purchase order, plus:
    • Invoice number
    • Vendor contact information
    • Credits or discounts
    • Payment schedule

Total amount due

Differences Between Purchase Orders and Invoices

What Is Similar About a Purchase Order and an Invoice?

Purchase orders and invoices share key similarities. Both documents are legally binding contracts that represent an agreement between the purchaser and the vendor, and the actions they contain are required.

In addition, they contain much of the same information, including order details, mailing information, quantity of goods or services, PO number, and pricing. In fact, the invoice generally contains all of the information from the PO, then adds the invoice number and payment information on top of that.

Purchase orders and invoices contain much of the same information but are used for very different purposes. Purchase orders request goods and services. Invoices request payment for goods and services.

Why Do Companies Use Purchase Orders?

Whether for a small business or large organization with a robust purchasing department, purchase order management is used for several reasons:

  • They Set Clear Expectations

    POs enable purchasers to clarify their needs to vendors. Both parties can use refer to them if orders aren’t delivered as expected.

  • They Help Manage Orders

    POs give procurement, finance, and operations teams official documentation of incoming or pending deliveries—enabling them to track and manage orders more effectively.

  • They Help With Budgeting

    Once a PO is created, purchasers can factor these costs into company budgets and spend according to plan.

  • They are Legally Binding

    A PO serves as a legally binding document, but only after it is accepted by the vendor. This gives the purchaser legal assurance that they’ll receive their order and the vendor legal assurance that they’ll be paid for it.

  • They are a Key Part of Audit Trails

    Recording POs helps provide auditors with the details they’re looking for and ensures that there aren’t any financial discrepancies in the purchasing department.

The benefits above are geared toward purchasers, but POs are also important documents for vendors—who use them for order fulfillment and payment processing.

Purchase order software can provide these benefits and more, as it digitizes and automates the entire procure-to-pay process from purchase order to invoice.

Why Do Companies Use Invoices?

As mentioned earlier, invoices are the standard for requesting business-to-business payments, which is the main reason companies use them. But they are the industry standard for good reasons.

Companies use invoices because:

  • They Prompt Customers To Pay

    Most vendors don’t receive payment until after an invoice is sent to the purchaser. A phone call or email from their accounts receivable department won’t suffice to complete the business transaction.

  • They Provide Confirmation To Customers On What They Have Purchased

    Invoices describe exactly what you’re getting for your money in line by line detail, which gives accounting departments transparency into what different departments buy—along with projections for cash flow.

  • They Help Manage Payments

    Invoices show what goods or services were sold, how much money has been paid to date, and any outstanding charges—providing a formal way to manage business payments.

  • They are Legally Binding

    A sales invoice officially shows that goods or services were provided and when payment is expected. They show financial terms that must be adhered to—providing legal proof that payment is due and can be referred to if payment isn’t received.

  • They are a Key Part of Audit Trails

    Auditors require evidence of all money going in and out of businesses. Since invoices show exactly what a business charges its customers, they are a crucial part of this evidence.

The Benefits of Digital Purchase Orders and Invoices

For a small business owner, using purchase order and invoice templates with programs like Word or Excel may work temporarily, but as the company grows it can become overly time-consuming and hard to manage. Additionally, printing and mailing paper can be hard to manage while ensuring that nothing gets lost or destroyed.

Digital procurement software provides many benefits to the purchase order and invoicing process. It gives companies the ability to control their budgets, improve vendor sourcing practices, manage relationships with suppliers, and ensure that they both pay invoices on time and get paid through invoices on time.

As a company scales and grows, it makes sense to switch to add automation and pursue a policy of digital transformation in procurement—as finance teams will need to manage a more complex procure-to-pay process and ensure that they are getting the most value from their supply chain. The best way to achieve this is through digital procurement software.

Purchase Orders and Invoices Are Vital to Success

Invoices and purchase orders are a vital part of a company’s purchasing process. Understanding the roles that invoices and purchase orders play is important for anyone involved in purchasing goods or services on behalf of an organization.

What’s your goal today?

1. Use Planergy to manage purchasing and accounts payable

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