“We had $50K in surprise invoices hit our budget in one month. I had no idea what my team was buying.”

That quote is from the CFO of a mid-market biotech company. It is not a rare story.

It happens at mid-market companies every month. Someone needs something, they order it, and you find out when the invoice lands on your desk. No purchase request. No approval. No warning.

The problem has a name: unauthorized employee spending, or maverick spending. Unauthorized employee spending is any purchase made without going through your company’s required approval process. It is not a sign of bad employees. It is a sign of a broken process.

This guide explains exactly why unauthorized spending happens, why email approvals make it worse, and how to build a purchase approval process that stops the problem before the money leaves. We will also show you what this looks like inside ProcureDesk, procurement and accounts payable automation software built for mid-market companies that have outgrown spreadsheets but are not ready for an enterprise ERP.

Tired of surprise invoices?

ProcureDesk gives you a purchase approval process that works in 2-3 weeks, not 6 months.

Why Employees Buy Things Without Approval

Before you can fix unauthorized spending, you need to understand why it happens. Most controllers assume it is a discipline problem. It is almost never that.

The process is unclear

If employees do not know they are supposed to submit a purchase request before buying something, they will not do it. Many mid-market companies never wrote down the process. It just evolved. And when the process only exists in the controller’s head, it does not scale.

The process is too slow

If an employee needs a $200 piece of lab equipment to run an experiment on Thursday, and the approval email sits unread for three days, they will find another way. Usually that means a personal credit card and an expense report you see two weeks later.

There is no system enforcing the process

Email-based approvals and spreadsheet tracking make it easy to go around the process without anyone noticing. There is no automatic block on purchasing. There is no visibility dashboard. The process only works if people choose to follow it.

Why Email Approval Does Not Work

Most mid-market companies try to handle purchase approvals over email. Someone sends a message asking for approval. A manager replies yes or no. The employee places the order. Simple enough at 30 people. A disaster at 100 people.

Here is what actually happens with email-based approvals:

• No tracking. Requests get buried in inboxes. There is no dashboard showing what is pending, what was approved, and what was denied.
• No audit trail. When an auditor asks who approved a $15K vendor payment, the answer is ‘I think Sarah approved it in an email somewhere.’
• No budget check. The approving manager has no way to see real-time budget availability when they hit reply. They are guessing.
• No enforcement. If the employee does not wait for a reply, nothing stops them from placing the order anyway.
• No visibility for finance. The controller has no idea what requests are in flight. The first time they see the spend is when the invoice arrives.

Corporate cards from Ramp or Brex solve part of the problem but only on the visibility side. They show finance what was spent after the swipe. They do not stop the purchase from happening in the first place, and they do not create a PO that finance can match an invoice against. For physical goods from vendor catalogs, cards alone are not a control. They are an after-the-fact report.

The Four-Step Pre-Purchase Approval Workflow That Actually Works

The fix is a structured workflow that happens before the purchase order is sent to any vendor. Here is what a working purchase order approval process looks like.

Step 1: Purchase Requisition

Before anything is ordered, the employee submits a purchase request inside your procurement system. This is not an email. It is a structured form that captures:

• What they need and why
• The estimated cost and quantity
• The vendor they plan to use
• Which budget or project code it should come from

This step creates the paper trail before any money moves. It also forces the employee to think through the purchase before they hit send. Many impulse buys get dropped at this stage when someone has to put the justification in writing.

Step 2: Automated Approval Routing

Once the request is submitted, the system routes it to the right approvers based on rules you define. You do not need to manually decide who should see what. The system handles it.

Common routing rules include:

• Orders under $500 auto-approve
• Orders between $500 and $2,000 go to the department manager
• Orders over $2,000 go to the controller or CFO
• Orders from unapproved vendors always require a manual review

The approver gets a notification by email, Slack, or mobile app. They can approve or deny without logging into anything. The request waits in queue and does not get sent to the vendor until it is approved.

Step 3: PO Creation and Dispatch

Once approved, the system automatically creates a purchase order and sends it to the vendor. The employee does not need to do anything. Finance does not need to manually create a PO. It happens automatically.

This step matters because it closes the gap that causes most invoice problems. If every purchase flows through an approved PO, your AP team can match invoices to POs automatically. No PO means no payment. That policy alone eliminates the majority of unauthorized spending.

Step 4: Receipt and Three-Way Match

When the goods arrive, the employee confirms receipt in the system. This creates the third document in the chain: PO, receipt, and invoice. Your AP team runs a three-way match to confirm all three align before payment goes out.

If anything does not match, the system flags it for review. If everything matches, the invoice can move to payment automatically. No manual checking. No duplicate payments. No missed discounts.

Want to see this workflow in action?

We can show you how ProcureDesk sets up approval routing in under 15 minutes during a demo.

What This Looks Like in ProcureDesk

ProcureDesk is procurement and AP automation software built for mid-market companies with 100 to 1,000 employees. It sits in the gap between two extremes. On one side, enterprise platforms like Coupa and SAP Ariba serve companies with 1,000+ employees, run 6 to 12 month implementations, and require a dedicated procurement team to operate. On the other side, basic PO tools like Tradogram serve small teams under 100 employees but lack the approval depth, ERP integration, and audit trail mid-market finance teams need. ProcureDesk is the mid-market option: full procure-to-pay with white-glove onboarding in 2-3 weeks, no IT project, no enterprise complexity.

It sits on top of your existing accounting system and adds a full purchase control layer that QuickBooks, NetSuite, Sage Intacct, and Microsoft Business Central do not have on their own.
Here is how ProcureDesk handles each step of the pre-purchase approval workflow for teams who need purchase order approval software that works without adding complexity.

Employees shop without leaving the system

ProcureDesk connects to 200+ vendor punchout catalogs, including Amazon Business, Grainger, Thermo Fisher Scientific, and Staples. Employees log in, browse their approved vendors, and build a cart exactly like they would on Amazon. When they check out, instead of entering a credit card, the cart becomes a purchase request and goes into the approval queue.

There is no learning curve. There is no form to fill out manually. The process feels like normal shopping, which means employees actually use it.

Approval routing is automatic and configurable

You define the rules once during setup. ProcureDesk handles the routing from there. Approvers get notified by email, Slack notification, or mobile app. They can approve or deny with one click without logging into the system.

The approver also sees the live budget balance for the department before they approve. They are not guessing whether the purchase fits the budget.

POs go out automatically

Once a request is approved, ProcureDesk generates the purchase order and sends it to the vendor. You never have to manually create a PO. Finance never has to email a vendor. The vendor gets the PO, acknowledges it inside the system, and shares shipping updates directly.

Invoices match automatically

When the vendor invoice arrives, ProcureDesk uses OCR to read the invoice and match it against the PO and receipt. If all three match, the invoice is cleared for payment and pushed to your accounting system automatically. If there is a discrepancy, the system flags it and routes it for review.

This is how Equality Charter School cut their PO cycle time by 87%, reducing order placement from 5 days to under 24 hours. Their AP team stopped chasing down approvals and started processing invoices in hours instead of days.

In our onboarding work with mid-market customers, the pattern is consistent. Once every purchase flows through an approved PO, the surprise-invoice problem disappears in the first month.

The audit trail builds itself

Every purchase request, approval decision, PO, receipt, and invoice is stored in ProcureDesk with a timestamp and the name of the person who acted on it. When an auditor asks who approved a purchase, you pull the record in seconds.

How to Write an Unauthorized Spending Policy That People Follow

A purchase approval workflow is a process. A spending policy is the written rules behind it. Both are required. Here is what your policy needs to cover.

Purchase thresholds

Define the dollar amounts that trigger different approval requirements. Keep it simple. Too many tiers means too many exceptions. A common structure:

Approved vendor requirements

Employees should only be able to purchase from vendors on your approved list. Any purchase from an unapproved vendor should require additional justification and a higher approval level. In ProcureDesk, you can enforce this automatically.

Read more: Maverick Spend Control Techniques

No PO, no payment

This is the single most powerful rule in any unauthorized spending policy. If finance will not process an invoice without a corresponding PO number, employees learn quickly that they have to submit a purchase request first.

Here is what enforcement looks like in practice. A vendor submits a $3K invoice. Your AP team checks the system. There is no matching PO. The invoice goes back to the department head with a note. Submit a retroactive purchase request and get it approved before finance will process payment. That happens once or twice before employees stop placing orders without going through the process first.

The policy only works if it is enforced consistently. No exceptions for senior staff, no waving it through because the end of month is close.

Consequences for going around the process

This does not need to be punitive. It just needs to be clear. Employees who purchase without approval should know that invoices will not be paid until a retroactive PO is issued; they may be required to cover the cost personally if the purchase was truly unauthorized; and repeated violations will be escalated to their manager.

Common Mistakes That Make Unauthorized Spending Worse

Mistake 1: Waiting until end of month to review spending

By the time month-end arrives, the money is already spent. Real-time budget tracking in your procurement system lets you see what has been committed before invoices arrive.

Learn more: Procurement Spend Analysis Guide

Mistake 2: Building a process that is too complicated

If submitting a purchase request takes 20 minutes, employees will not do it for a $50 supply purchase. Keep the process as simple as possible. The goal is control, not friction. Most purchases under a certain threshold should be fast-tracked automatically.

Mistake 3: Not enforcing the policy consistently

If a senior employee goes around the process and finance processes the invoice anyway, everyone else sees that the rules do not actually apply. Consistency is what makes the policy work. The ‘no PO, no payment’ rule only protects you if it is never waived for convenience.

Mistake 4: Assuming implementation takes months

Most controllers who have lived through an ERP rollout assume any new finance system means a 6-month project, an IT dependency, and a disruption to their team mid-close. That assumption keeps a lot of companies stuck with email approvals longer than they need to be.

Purchase approval systems are not ERP implementations. ProcureDesk deploys in 2-3 weeks with white-glove setup included. There is no IT involvement, no configuration work for your team, and employees need no training. The controller owns the entire implementation.

See how the setup works.

How to Measure Whether Your Approval Process Is Working

Once you have a process in place, you need to track whether it is actually controlling spend. These are the metrics that tell you whether your approval workflow is doing its job.

Building the Business Case for a Purchase Approval System

If you are reading this as a controller or accounting manager, you may need to convince your CFO that this is worth the investment. Here is how to frame it.

The cost of doing nothing

According to Ardent Partners’ AP Metrics That Matter 2025 benchmark, the average cost to process a single invoice manually is $12.88. Best-in-class AP teams that have automated the process spend $2.88. If you process 200 invoices a month, that is a $2,000 monthly difference. $24,000 a year. And that number does not count duplicate payments, missed early-payment discounts, or the hours your team spends chasing approvals instead of closing the books.

ProcureDesk customers consistently move that number. Coast Flight reduced invoice processing time by 30% after implementation. myDNA cut their month-end close from 7-8 days to 3 days. The shared driver in both cases: every purchase had a PO, every invoice had a match, and the AP team stopped doing manual reconciliation work.

The implementation is faster than you think

One of the most common objections is the assumption that deployment takes months. ProcureDesk is live in 2-3 weeks. Setup is included at no extra cost. You do not need an IT team.

Read more: How to automate purchase orders.

The ROI is measurable

Calculate your current average invoice processing cost. Multiply by monthly invoice volume. Compare that against the cost of a system that cuts it by 50% to 70%. Most ProcureDesk customers see positive ROI within the first quarter.

For more detail: Purchase Requisition Software for mid-market companies

The Bottom Line

Unauthorized employee spending is not a people problem. It is a process problem. When employees do not have a clear path to get purchases approved, they find their own way. And finance finds out when the invoice arrives.

The fix is a structured pre-purchase approval workflow: purchase request, automated routing, PO creation, and three-way match at invoice. When every purchase flows through that process, surprise invoices stop. Budget overruns get caught before they happen. And your audit trail builds itself.

ProcureDesk gives mid-market companies this workflow in 2-3 weeks without disrupting their existing accounting system. If you are closing the month and still reconciling surprise invoices against a spreadsheet, see what a working purchase control process looks like in a 15-minute demo.

Ready to stop surprise invoices?

ProcureDesk sets up purchase approval workflows in 2-3 weeks. Full setup included. No IT required.

Related Resources

Internal Resources

• Purchase Order Approval Software
• Guide to the Purchase Order Approval Process
• How to Automate Purchase Orders: 7-Step Framework
• Maverick Spend Control Techniques
• Procurement Spend Analysis Guide
• Purchase Requisition Software
• Purchase Order Management Software
• How to Create a Purchase Order: Step-by-Step Guide