How to Automate Purchase Approvals Using Power Automate
An automated purchase approval workflow in Power Automate replaces the most expensive part of an informal approval process: the time spent chasing. Requests submitted via form are automatically routed to the right approver based on amount, delivered as a one-click approval in Teams or Outlook, escalated automatically if no response comes, and logged with a full audit trail. The approver still makes the decision. The workflow handles everything else - and makes every approved or rejected request visible to finance in real time.
What a purchase approval workflow does
A purchase approval workflow in Power Automate intercepts purchase requests - submitted through a form, a SharePoint list, or an email to a designated address - routes them to the appropriate approver based on the request amount and category, captures the approval decision, notifies the requester, and logs the outcome with a full audit trail.
Unlike invoice approval (which approves after the fact), purchase approval happens before the purchase is made. The workflow enforces the organisation's delegation of authority: who can approve what amounts, whether multiple approvers are needed for larger purchases, and what happens when an approver is unavailable.
The workflow components
- 01
Purchase request submission
Requests are submitted via a Microsoft Forms form or a Power Apps canvas app. The form captures: requester name, department, supplier name, description of purchase, amount (including GST), required by date, business justification, and any supporting documentation. On submission, Power Automate triggers automatically.
- 02
Approval tier routing
Based on the submitted amount, the workflow routes to the appropriate approval tier. Common configurations: under A$1,000 - direct manager approval; A$1,000 to A$10,000 - operations manager or finance manager; above A$10,000 - director or CEO approval. These thresholds and approvers are configurable in the workflow without code changes.
- 03
Approval request delivery
The approver receives an Adaptive Card in Microsoft Teams or an approval email in Outlook. The card displays all relevant request details - supplier, amount, business justification, required by date - and provides Approve and Reject buttons with an optional comment field. The approver acts without leaving Teams or Outlook.
- 04
Sequential or parallel approval for larger amounts
For purchases requiring multiple approvals - for example, both the finance manager and the CEO for amounts above A$25,000 - the workflow can route approvals sequentially (one after the other, each seeing the previous decision) or in parallel (both receive the request simultaneously, with the purchase proceeding only when all approve).
- 05
Escalation handling
If an approver does not respond within a defined period - typically 24 hours - the workflow sends a reminder. After a second reminder, the workflow can escalate to the approver's manager or flag the request for manual follow-up. This eliminates the situation where a time-sensitive purchase is held up because an approver is out of office.
- 06
Notification and logging
On approval or rejection, the requester is notified via Teams or email with the decision and any comments. All requests, regardless of outcome, are logged to a SharePoint list with the decision, approver name, timestamp, and comments. This creates the audit trail required for financial controls and budget review.
- 07
Integration with procurement and accounting
If approved, the workflow can create a purchase order in your accounting system (Xero, MYOB, QuickBooks) via API, or add the approved request to a procurement tracking list. This eliminates the data re-entry step between approval and procurement processing.
Comparison with a manual purchase process
Manual vs automated purchase approval comparison
| Step | Manual process | Automated workflow |
|---|---|---|
| Request submission | Email to manager, inconsistent format | Structured form - consistent data captured every time |
| Routing to approver | Manual forwarding, approver may not be obvious | Automatic routing based on amount and department rules |
| Approval action | Email reply, often lost in inbox | One-click in Teams or Outlook with optional comment |
| Multi-level approval | Sequential email chains, no tracking | Parallel or sequential routing with status tracking |
| Reminder / escalation | Manual follow-up by requester | Automatic reminders and escalation |
| Requester notification | Reply email if remembered | Automatic notification with decision and comments |
| Audit trail | Email chain - inconsistent, hard to retrieve | Structured SharePoint log with timestamps |
| Budget visibility | No real-time view | SharePoint dashboard shows all pending and approved spend |
| Accounting system update | Manual entry by finance team | Automatic via API integration |
Technical requirements
- Microsoft 365 Business Premium or Power Automate Premium licence for the service account running the flow
- Microsoft Forms for the request intake (included with Microsoft 365)
- SharePoint list for logging approved and rejected requests (included with Microsoft 365)
- Microsoft Teams for approver notification delivery
- Optional: Power Apps for a more structured intake experience than Forms allows
- Optional: API access to accounting system (Xero, MYOB, QuickBooks) for automated purchase order creation
Delegation of authority policy
The automation enforces whatever delegation of authority rules you define - it does not create those rules. Before building the workflow, the business needs a documented delegation of authority policy: who can approve what amounts, whether any purchase types require different routing regardless of amount (IT purchases, marketing spend), and what happens for emergency purchases outside business hours.
The workflow is the enforcement mechanism for the policy. If the policy is unclear or contested, that needs to be resolved before the workflow is built - not after.
The benefit of automating purchase approvals is not just efficiency - it is control. Businesses that have implemented purchase approval workflows typically find that the visibility into pending and approved spend prompts better budget management. When every purchase request is visible in a SharePoint list, the finance manager can see what is in the pipeline before month end rather than discovering it on the credit card statement.
Sources & accuracy
Last reviewed: 5 October 2026 · Microsoft product capabilities, licensing and configuration options change regularly. Verify current details at learn.microsoft.com.
Next step
Automation Sprint
The Automation Sprint designs and builds a targeted workflow - including purchase approval automation - in a fixed timeframe at a fixed price. Includes delegation of authority review, workflow design, build and testing, and handover documentation.
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