The complete guide to the purchase order process
Purchase orders are not just bureaucratic paperwork. They create legally binding contracts between buyers and sellers, enable budgeting, manage expectations, and provide audit evidence. Discover the complete purchase order workflow from requisition to delivery, plus automation strategies to eliminate manual errors.
PO processes need structured approvals and tracking.
Approval Management Made Easy
Summary
- Purchase orders form legally binding contracts, not bureaucratic paperwork - POs come at the start (detailing what supplier must deliver), invoices come at the end (requesting payment). Once sent and accepted, POs create enforceable contracts with clear terms for resolving disputes
- The four-stage process manages expectations on both sides - Buyer creates purchase requisition (getting internal approval), sends PO to supplier (with quantity, type, prices), supplier approves and acknowledges receipt, buyer officially records the order so supplier can fulfill it
- POs prevent budget chaos and enable forecasting - Without them, a $1M invoice could arrive demanding payment in 30 days with zero warning. With POs, finance departments budget in advance, suppliers track incoming orders and manage inventory with confidence
- Automation eliminates manual chaos across seven document types - Requisitions, purchase orders, quotes, acknowledgements, advice slips, receipts, and invoices create massive opportunities for human error and lost paperwork when handled manually. Software tracks process status and provides instant access to records. See how Tallyfy automates finance workflows
If you have worked in a corporate environment or within the financial or supply industries, you will be familiar with purchase orders. Approval workflows appear in about 93 of our customer discussions at Tallyfy, and these documents are far more important than most people realize. Whether you deal with them on a daily basis or it is just a phrase you have heard from time to time, how much you might know will vary but there is still lots to learn about the purchase order process.
They might seem like an extra level of bureaucracy that has been invented by someone obsessed with paperwork and fussy processes, but they play a hugely important role in how businesses operate and we will demonstrate why here, along with everything else you need to know.
What is a purchase order?
A purchase order (PO) is a document issued by a buyer to the seller, providing the information about the details of the order. That’s the quantity, type of product, prices, etc.
You might be wondering, “what’s the difference between a purchase order and an invoice? It’s an easy misconception to have because they both involve a customer and a supplier arranging payment for products or services.
But the key difference is in the timing, as a purchase order (as the name suggests) is used at the start of the process to form a legal contract between supplier and customer and lay out the details of exactly what the supplier will be required to deliver.
An invoice is generated at the end of the process by the supplier, using the information from the purchase order to request the agreed payment from the customer.
What does a purchase order contain?
Here are some of the essentials that a purchase order tends to contain:
- PO number (which is then referenced in the invoice to connect the two documents, something that is particularly important for finance departments in large companies)
- Contact information for the customer
- Payment information
- Description and quantity of goods/services ordered
- Invoice and delivery address (if different)
What is the purchase order process?
There are a number of stages involved in the purchase order process. These can vary from company to company, but the ones listed below are the most commonly used:
- Purchase requisition is created - This takes place within the company making the purchase and sees the person responsible for the purchase requesting approval from finance and line managers to do so.
- Purchase order is sent - Assuming the first stage does not end with a firm “no”, the purchase order is created and sent to the supplier, detailing what is wanted and providing the information the supplier will need when creating their invoice.
- Supplier approves purchase order - Again, this assumes that the supplier is happy with the purchase order they have received. Once they have reviewed it they will acknowledge receipt and acceptance of the order.
- Buyer records purchase order - Now that the binding contract has been agreed, the purchasing company will officially record the purchase order and the supplier will start to do what is required of them to fulfill the order.
What is the purchase order process used for?
The purchase order process has many purposes beyond the straightforward answer of acting as the initial agreement of what work will be completed by the supplier.
Here are some of the ways that using purchase orders will benefit your business:
Budgeting
Particularly in companies where there are constant streams of income and expenditure flowing through the finance departments, purchase orders are essential to ensure that there are no nasty surprises when invoices come in.
Without the purchase order process, an invoice for $1m could arrive, demanding payment within 30 days, and the finance department could have had no warning that it was due, making it difficult to find that money in time to pay it.
With a purchase order, they will have been able to budget for it in advance, and that works the other way around too, as the finance staff at the suppliers have been able to know that payment will be coming in even before the invoice has been sent.
Managing orders and expectations
As well as being able to forecast what the budgets will be, the purchase order process can help suppliers track incoming orders and manage inventory levels with knowledge of what is expected.
Purchase orders are a set in stone way of agreeing on these expectations at both ends of the supply workflow, so the suppliers know what they will be supplying and can prove that it is what was requested if there are any disputes.
Or, of course, vice versa. This saves everyone time.
Evidence for financial audits
In some smaller businesses, orders can be placed and recorded on scraps of paper, which might work fine for their internal processes, but isn’t the kind of solid and substantial evidence needed for a financial audit.
Using purchase orders demonstrates a healthy flow of orders and income or sensibly-managed expenditure and is probably the best way to prove to auditors, banks and tax agencies that your business is doing things the right way.
Legally binding contract
Once a purchase order has been sent and accepted by the supplier, it acts as a legally binding contract between the two parties, so if a dispute arises and there is any question of payment or goods/services being withheld, the contract between them is clear. Anyone acting as arbitrator or mediator between parties in dispute has a document detailing exactly what has been agreed, and it should be easy to come to an agreement.
Making the purchase order process run smoothly
Like any business process, there are always ways in which the purchase order process could be sped up or made more efficient. In my experience, the best way to do that is through business process automation.
During the purchase of goods and services, companies can generate a lot of paperwork, including:
- Requisitions
- Purchase orders
- Quotes
- Acknowledgements
- Advice slips
- Receipts
- Invoices
If this is all being done manually, that’s a lot of paperwork that needs to be generated, recorded, distributed and filed away, and also offers plenty of opportunities for human error to creep in and cause chaos. In our experience, organizations running purchase order processes across multiple departments and approval tiers often find that manual routing alone accounts for dozens of hours per month in administrative overhead.
The physical paperwork also has the potential (and tendency) to disappear, leaving gaps in the workflow and evidence that can cause problems at audit time or in disputes. Automating the purchase order process minimizes the possibility of these issues.
Using a software solution means that it’s easy to track where the process is up to and to refer to the purchase order quickly when required. It’s more efficient, more accountable, quicker and safer.
Ready-to-use purchase order templates
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About the Author
Amit is the CEO of Tallyfy. He is a workflow expert and specializes in process automation and the next generation of business process management in the post-flowchart age. He has decades of consulting experience in task and workflow automation, continuous improvement (all the flavors) and AI-driven workflows for small and large companies. Amit did a Computer Science degree at the University of Bath and moved from the UK to St. Louis, MO in 2014. He loves watching American robins and their nesting behaviors!
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