In the process of doing business, sales invoices and purchase orders are two forms that are used in the clear understanding of transactions between two parties. In an organization with a sales department and a purchasing department, both these departments need to use one or both forms for internal and external purposes. 

A purchase order is a purchase request from the buyer to the seller, whereas an invoice is a payment request from the seller to the buyer. The terms are sometimes used interchangeably by customers. Although purchase orders and invoices have many similarities, they are two separate documents with various purposes. The critical difference between PO and invoicehas been depicted in the form of an Infographic. Check the infographic below-

Invoice VS PO

This infographic has shown you the differences between an invoice and a purchase order. Invoice software should be what every business needs for invoicing procedures because it will make life easier! 

Purchase Order – Detailed Explanation

Let’s learn about Purchase Order in detail including its purpose and elements. 


A Purchase Order (PO) is a formal document that a buyer issues to the seller signifying buyers interest in purchasing goods and services from the seller. 


This document serves as proof of goods and services that are asked so that there are no disputes between the seller and buyer afterwards. 

Components Of Purchase Order

  1. PO Number: This is the unique identification number of a purchase order. It helps both parties keep track of multiple orders and refer to them easily.
  2. Vendor Information: It includes the vendor’s name, address, contact information, and sometimes a tax identification number.
  3. Item Details: This part describes each item in detail, specifying product codes, descriptions, and any other relevant information.
  4. Quantity and Price: The quantity of each item and the total cost is clearly stated.
  5. Shipping and Payment Terms: It specifies the shipping method, destination, expected delivery date, and payment terms.

Types of Purchase Orders

  1. Standard Purchase Order: This is your go-to PO for one-time, straightforward transactions. It specifies the products or services, quantities, prices, and delivery terms. Use it for routine orders without ongoing commitments.

Use: When you need to order a one-off product or service, like office supplies or a single repair job.

  1. Blanket Purchase Order: When you’re planning to make multiple orders from a single supplier over a period (e.g., a year), the blanket PO is your friend. It sets the terms for all those future purchases in one document, simplifying the process and ensuring consistent pricing.

Use: When you anticipate multiple orders from the same supplier over a set period, such as office cleaning services for a year.

  1. Contract Purchase Order: For long-term partnerships, a contract PO is the way to go. It outlines all the terms and conditions, such as pricing, delivery schedules, and quality standards, for a more extended period, often covering an entire project or service.

Use: A Contract PO is your choice for complex, ongoing projects or services that require a clear and long-term commitment, like IT services or a year-long consulting engagement.

Pros And Cons Of Using Purchase Orders

1. Clarity And Specificity: POs offer clear, written records of your orders, specifying items, quantities, and agreed prices, reducing misunderstandings. 1. Administrative Overhead: Creating and managing POs can be time-consuming, involving paperwork and data entry.
2. Budget Control: POs help you control your spending by setting a predetermined budget for each purchase. 2. Rigidity: POs are binding and changing them can be complicated, often requiring amendments or canceling and reissuing.


3. Tracking And Accountability: POs track orders, ensuring on-time delivery and boosting accountability for both buyer and seller. 3. Not Ideal For All Transactions: Smaller or routine purchases may not warrant the use of a PO, making it an impractical choice.
4. Efficient Inventory Management: POs improve inventory management, providing insight into incoming orders to prevent stockouts and overstocking. 4. Limited Supplier Relationships: Relying heavily on POs may hinder the development of more flexible and trusting relationships with long-term suppliers.

Invoice – Detailed Explanation

Let’s explore Invoice in detail including its purpose and elements.


An Invoice is a manually or online-created legal document that a seller provides to the buyer demanding payment for goods/services.


The primary purpose of an Invoice is to request payment for the products or services that have been supplied as per the Purchase Order.

It also acts as a financial record and helps both parties maintain transparent accounting practices.

Components Of Invoice

  1. Invoice Number: Just like the Purchase Order, every Invoice comes with a unique identifier, making it easy to trace and reference in financial records.
  2. Seller’s Information: The seller’s details are prominently displayed, including their name, address, contact information, and sometimes their tax identification number.
  3. Buyer’s Information: The buyer’s details are also included on the Invoice, providing a clear indication of who should make the payment.
  4. Itemized Products/Services: List of all products or services provided to the buyer, similar to the details on the Purchase Order.
  5. Total Amount: The total amount to be paid, including any applicable taxes or discounts.
  6. Payment Terms: The invoice also outlines the payment terms, specifying the due date and the method of payment.

Types of Invoices

Here’s a rundown of various invoice types:

  1. Pro Forma Invoice: This type serves as a preliminary bill, often used for customs purposes. It details the expected costs before the final transaction, providing clarity to both parties about what to expect.

Use: A Pro Forma Invoice is handy when you’re shipping internationally and need to clarify costs and goods upfront for customs clearance.

  1. Commercial Invoice: The most common invoice type, it’s the official bill issued after the delivery of goods or services. It includes a breakdown of costs, payment terms, and is legally binding.

Use: When you’re shipping internationally and need to clarify costs and goods upfront for customs clearance.

  1. Recurring Invoice: For services that are billed at regular intervals, such as monthly subscriptions or rent, recurring invoices automate the process by sending the same invoice repeatedly over the agreed-upon timeframe.

Use: Recurring Invoices are excellent for ongoing services, like software subscriptions, rent, or retainer agreements. They keep the billing process smooth and predictable.

Advantages And Challenges Of Using Invoices

1. Flexibility: Invoices are versatile and suitable for various types of transactions, from one-time sales to ongoing services or subscription billing. 1. Billing Errors: Mistakes on invoices can lead to disputes or delayed payments. It’s essential to double-check the accuracy of each invoice.
2. Timely Payments: Invoices specify due dates, helping ensure you get paid on time.


2. Vulnerable to Fraud: Invoices are susceptible to fraud, as scammers may send fake invoices or manipulate legitimate ones.
3. Payment Tracking: Invoices often come with features that allow you to track when an invoice is opened, viewed, and paid, giving you real-time payment insights. 3. Variability: Different customers may have unique invoicing requirements, making it necessary to adapt your invoicing process for each client.

Why Understanding the Difference Matters

A. Legal and Financial Implications

Differentiating between purchase orders and invoices has significant legal and financial implications.

A purchase order is a commitment to buy, with terms and conditions that protect both parties. Not following PO terms can lead to legal issues and financial liabilities.

On the other hand, invoices demand payment. Ignoring invoice payment terms can result in late fees, strained vendor relationships, and even legal action.

To stay compliant and financially sound, understanding this difference is crucial.

B. Inventory Management

Inventory Management

Distinguishing between POs and invoices is vital for effective inventory management.

A purchase order sets your inventory needs, preventing over-ordering or under-ordering, saving costs, and satisfying customers.

Invoices record delivered goods or services. Matching them to POs ensures precise inventory tracking, saving money, and meeting customer demand.

A. Dispute Resolution

Clear understanding of POs and invoices streamlines dispute resolution. Discrepancies between the two become easier to identify and resolve.

Well-documented POs and invoices simplify dispute resolution, helping both parties agree on fair resolutions when conflicts arise.

Common Misconceptions

1. Mistakenly Treating Invoices as POs

One common pitfall is mistakenly treating invoices as purchase orders or vice versa.

It’s crucial to remember that a purchase order is a request to procure goods or services, while an invoice is a request for payment for those goods or services already delivered.

2. Confusion in Record-keeping

Proper record-keeping is the backbone of efficient financial management. Mixing up purchase orders and invoices in your records can lead to a chaotic and error-prone accounting system.

To prevent record-keeping confusion, establish a systematic approach for filing and organizing your POs and invoices.

How To Match POs With Invoices

Match POs With Invoices

  1. Matching the Purchase Order (PO): Start by comparing the details on the invoice with the corresponding purchase order. Ensure that the quantities, descriptions, prices, and other terms align.
  2. Matching the Receiving Report: If your organization uses receiving reports, confirm that the items listed on the invoice were actually received and that the quantities match.
  3. Matching the Invoice: Finally, check the invoice itself. Ensure that the amounts, payment terms, and any applicable discounts or taxes are in line with the Purchase Order and Receiving Report.

Resolving Discrepancies

Discrepancies are not uncommon in the matching process, and it’s essential to have a system in place for resolving them:

  1. Communication: Establish a clear line of communication with your vendors. If there’s a discrepancy, reach out to them promptly to clarify any issues. Often, these discrepancies are simple errors or misunderstandings that can be easily resolved through communication.
  2. Documentation: Maintain a record of all correspondence related to discrepancies. This documentation can be valuable for auditing and for tracking the resolution process.
  3. Approval Workflow: In some cases, you may need to involve higher management for approvals if the discrepancies involve significant amounts or contractual matters. Ensure you have a workflow for seeking these approvals.
  4. Adjustments: Make necessary adjustments in your financial records to rectify the discrepancies. Ensure your accounts are accurate and up-to-date once the issues are resolved.

Best Practices For Handling Purchase Orders And Invoices

Efficient Record-keeping

Efficient record-keeping is the foundation of successful PO and invoice management. Here are some friendly tips:

  1. Digitalization: Embrace digital tools and software to store and manage your POs and invoices. It makes retrieval and tracking easier and more environmentally friendly.
  2. Consistency: Establish a standardized naming and filing system. Make sure everyone in your organization follows it, making documents easy to locate.
  3. Backups: Regularly back up your digital records to prevent data loss.

Communication with Vendors

Good vendor communication can help prevent issues before they arise:

  1. Clarity: Be crystal clear about your expectations in the purchase order. Avoid vague or ambiguous terms that can lead to misunderstandings.
  2. Timely Updates: Keep your vendors informed about any changes in the purchase order or delivery schedule. This can prevent last-minute discrepancies.
  3. Feedback: Provide constructive feedback to vendors when discrepancies occur. It helps in improving future transactions.

Software and Automation

Leveraging technology and automation can greatly enhance your PO and invoice management:

  1. Use Accounting Software: Invest in accounting software that streamlines the entire process. It can automate tasks like data entry and reconciliation.
  2. Email Alerts: Set up email alerts for due dates, discrepancies, and approvals.
  3. Regular Updates: You must keep your software updated to get benefits from the latest features.

Legal Implications and Regulations

Key considerations include:

Mandatory Information: Ensure your invoices and purchase orders contain essential details like buyer and seller information, product or service descriptions, prices, and payment terms.

Tax Compliance: Adhere to tax regulations, such as including tax identification numbers and accurately calculating and charging taxes.

Data Retention: Comply with local regulations for retaining invoices and purchase orders for audit and legal purposes.

How Non-Compliance Can Affect Your Business

Failure to meet legal requirements can result in:

  • Financial Penalties: Fines and penalties imposed by tax authorities.
  • Disputes and Delays: Disputes with customers or suppliers, leading to payment delays.
  • Tax Troubles: Tax audits and potential additional tax liabilities.
  • Reputation Damage: Harm to your business reputation and partnerships.

Which On-Demand Invoicing Software Can Generate Both PO And Invoices?

Invoicera is an online invoice generator software with over 18 years of expertise that manages Purchase Order Management for more than 4 million firms globally. The invoicing software aids in the preparation and management of every business purchase order and Invoice. It also allows you to capture all your communications to keep a thorough track of all your documents.

PO And Invoices

You may also keep a record of all your conversations and documents with this tool. It can automate the following areas of your business –

  • Online time tracking
  • Auto invoicing and payments
  • Expense management
  • Recurring/subscription billing
  • Workflows
  • Client/vendor panels
  • Multilingual & multi-currency support
  • 14+ Online payment gateways
  • APIs for 3rd party integration
  • Subcontractor billing and time management
  • Purchase order management
  • Financial reporting & analysis
  • Staff permissions

Connect with us today to know more about our intelligent billing solutions. We look forward to working with you soon!

Sign up today to try Invoicera for free here.

Must Watch this video for a difference b/w Invoice and Credit Memo.

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Ques. What is one major difference between a purchase order and an invoice?

Ans. PO number is a unique identifier for each purchase order. The invoice number, on the other hand, is used to identify each Invoice.  

Ques. How will you differentiate between Invoice and receipt?

Ans. An invoice is created first, followed by a payment request. On the other hand, a receipt is generated after cash has been paid as proof of service to show that money was received.

Ques. What is the difference between a PO invoice and a non-PO invoice?

Ans. When a purchase requisition procedure is in place, the purchase will be activated by a pre-approved purchase order (PO) sent to the supplier. 

A non-PO invoice, also known as an expense invoice, will be delivered by the supplier when purchases are made outside of the authorized purchasing process.

Ques. What information is conveyed by Invoice and PO?

Ans. The Invoice confirms that the sales have occurred, whereas PO defines the terms of the sale.

Ques. Does Invoicera support auto invoicing and PO management both?

Ans. Yes, Invoicera supports both auto invoicing and PO management. It is online invoicing software for small businesses, including invoicing, billing, time tracking & more. Invoicera is compatible with Mac & PCs, iOS & Android device management.