The supplier needs a purchase order number before sending material to the jobsite. You need to issue it, keep the approved amount on record, and find it again when the invoice arrives. Zoho Inventory, Odoo Purchase, and self-hosted ERPNext are free purchase order software options to evaluate. Their free offers cover different scopes, so start with who needs access and what happens after the order is sent.
This comparison uses official pricing and documentation checked October 14, 2026. It covers ongoing free offers, including software you operate yourself, and excludes temporary trials. The recommendations are based on documentation rather than hands-on testing. Permute publishes this article and sells connected business data and custom applications; its commercial scope appears separately below.
Keep the current purchasing setup if it preserves approvals and outstanding balances and the proposed move only saves a small subscription. Price the same buyer and receiver accounts, monthly order volume, and twelve-month period for each candidate. A free license does not include the time needed to map suppliers, configure approvals, or maintain a self-hosted installation.
Decide what the office needs beyond a printable order
A PDF generator can produce a document for the supplier, but you still need a place to record approval, deliveries, changes, and closure. If your current register handles those steps, replacing the document template may be enough. If different people maintain conflicting copies, evaluate a shared purchasing workflow and its permissions.
Count the people who will create orders, authorize purchases, confirm deliveries, and check invoices. These may be different roles even in a small business. A free single-user account needs an agreed handoff outside the application; sharing a password makes it harder to tell who changed an order. For broader job-level requirements, the construction purchase order software comparison covers the project purchasing decision.
- Approval: can the person entering an order also approve an amount they are not authorized to spend?
- Receiving: can you record one delivery while leaving the undelivered quantity open?
- Changes: can a reviewer find the prior approved amount after a supplier changes the order?
- Job references: does the project code survive an export alongside each order line?
- Exit: can you retrieve open orders and their supporting records after changing plans?
Three free offers with different operating costs
| Option | What is free | Reason to consider it | Constraint to check |
|---|---|---|---|
| Zoho Inventory | US hosted Free: 20 purchase orders per month, 1 user, 1 location | A small order volume managed by one office user | Separate monthly bill limit and access needed by approvers |
| Odoo Purchase | One App Free on Odoo Online, including required dependencies | Purchasing within a defined single-app scope | Additional standalone apps can require a paid plan |
| ERPNext | Open-source software you can self-host | Purchasing with a team responsible for operating the software | Hosting, setup, backups, and support still need resources |
Zoho Inventory for a small hosted purchasing register
Zoho’s US pricing comparison lists 20 purchase orders and 20 bills per month on Free, with one user and one location. The separate allowance of 50 orders per month should not be read as the purchase order allowance. Estimate purchasing volume from recent months, including busy periods, before relying on the free tier.
Zoho’s purchase receive documentation describes recording all or part of a delivery against an order. Test that process with a partial shipment, then inspect the outstanding quantity. The single-user limit deserves its own decision: if field staff and an independent approver need accounts, price the required plan instead of assuming the free account will cover them.
Odoo Purchase when the single-app scope fits
Odoo’s One App Free terms cover one app on Odoo Online with unlimited users and its required dependencies. Odoo offers Purchase for supplier requests and purchase orders. That makes it a candidate when several people need purchasing access and the required work fits the free application scope.
List the apps needed for your proposed workflow before installing them. An app required by Purchase and another app you elect to add are different cases under the offer. Confirm whether the receiving and accounting features you need introduce additional apps or a paid subscription. Do not assume that every feature shown across the Odoo suite belongs to a free Purchase setup.
If the proposed Odoo setup does not fit the wider workflow, the Odoo alternatives comparison covers replacement scope and maintenance ownership. Keep that broader decision separate from testing whether a free purchasing app handles the office’s current order volume.
ERPNext when someone can own the installation
Frappe’s ERPNext pricing page distinguishes free open-source software from paid hosting and implementation. You can run it on your own server without paying a software subscription. The purchase order documentation describes creating receipts and supplier invoices from an order, monitoring received and billed quantities, and closing orders or selected items.
This is a candidate if you have someone responsible for configuration, updates, backups, and recovery. Assign that responsibility before putting live orders into it. Your evaluation should include a restore exercise and a check of user permissions, because the purchasing office still needs access when the person who installed it is unavailable. Managed hosting is a separate cost.
Try a partial delivery and a canceled balance
Use a hypothetical order for 100 units at $10 each, excluding tax and freight. The original approved amount is $1,000. The supplier delivers 60 units, then you agree to cancel the remaining 40. The record should preserve the original approval and the $400 cancellation while showing that no further delivery is expected. Keep the delivery evidence for the 60 units.
The site receiver confirms what arrived. The buyer records the agreed cancellation and keeps the supplier’s confirmation, while the person checking the invoice matches the billed quantity to the accepted delivery. Decide who can reopen a closed order. A canceled balance and an unreceived balance should not look identical to the person preparing the next purchasing report.
Agree on what the report calls an open commitment: for example, approved order value that has not been canceled or billed. Under that definition, receiving material alone does not remove its value from the commitment. If your report instead tracks undelivered orders, label that measure separately. The construction job cost report explains why purchase commitments and posted costs need consistent treatment.
Approved quantity and job reference
Receipt, cancellation, and approval retained
Where Permute fits with purchasing records
Permute sells connected business data and custom applications. We can scope reporting that combines supplied purchase order records with supported accounting sources. The work includes matching supplier and job references, with uncertain matches kept visible for review.
Your team defines which order statuses count as commitments and when billed amounts leave that measure. We apply those rules to the combined records so the office manager can trace a reported balance to its order and accounting evidence. Permissions determine who can inspect the underlying data. The construction cost management software article covers the broader budget and cost reporting decision.
Explore the records behind a purchasing report
Start with an available source and inspect the fields needed to connect orders to job costs.
Keep purchasing controls with their responsible system
Permute is a separate commercial service, not a free purchase ledger or one of the free options above. This reporting example does not promise native connections to every named tool, issue orders to suppliers, or update a purchasing system. Those operations require a separately verified scope and responsible owner. Keep approval and receiving work in the purchasing application unless another implementation has been agreed and validated.
If you move open orders, preserve their source references and supporting records before ending the old arrangement. The ERP migration article covers ownership and validation during a move. Check your export while you still have access to resolve missing history.
Choose the free scope your office can maintain
Zoho Inventory is a candidate for low-volume purchasing with one user, Odoo Purchase for a single-app workflow, and ERPNext for a team prepared to operate its own software. Compare the needed access and operating work alongside the subscription price. Follow an order through delivery and cancellation before choosing. The office should be able to issue the supplier’s order number and explain the remaining balance afterward.
Discuss purchasing reports across your tools
Bring an order export, a job cost report, and the definitions your team needs them to share.
Questions about starting with free purchasing software
Does the supplier need an account in the same software?
Decide how suppliers will receive orders and confirm changes before selecting a tool. An emailed document may fit your process, provided the office keeps the response with the order record. Test the proposed handoff with the supplier rather than assuming a portal invitation will be accepted.
What happens when material is ordered before the office creates the PO?
Record the actual sequence and who authorized the purchase. Keep the supplier reference so the later invoice can be matched without creating a duplicate order. Agree on an exception process with the person responsible for purchasing approvals instead of making a late entry appear to be advance approval.
Should I move software as soon as I exceed a free limit?
Compare the upgrade cost with the work of moving active orders and checking their history. A paid tier may preserve a process your team already understands. Keep an export available, but make the decision before a limit interrupts the next purchasing cycle.