How to Convert PR to PO in SAP (Purchase Requisition)
Olivia Turner
⚡ Smart Summary
Convert a Purchase Requisition to a Purchase Order in SAP through transaction ME21N. A released requisition number is entered as the reference, and SAP copies item data while applying info record price and order unit.
What Happens When a Requisition Becomes an Order?
Conversion turns an internal request into an external commitment. The requisition asked the purchasing department to buy something; the purchase order tells a named vendor to supply it at an agreed price on an agreed date.
SAP does not copy the requisition blindly. Three sets of master data override what the requisitioner typed:
- Purchase info record: Supplies the net price, the order unit, the planned delivery time, and the tolerance limits for the vendor and material pair.
- Vendor master: Supplies payment terms, incoterms, and the purchasing organisation data used in the order header.
- Material master: Supplies the purchasing group, over and under delivery settings, and the goods receipt processing time.
This is why a quantity entered in pieces can appear in pallets on the order, and why the net price may differ from the valuation price shown on the requisition. Both are expected behaviour, not errors. Maintaining the purchase info record correctly is therefore the single biggest influence on conversion accuracy.
Process to Convert PR to PO in SAP
Upon release purchase requisitions can be converted into purchase orders. This can be accomplished in transaction code ME21N. Process for converting a PR into PO is straight forward, and the steps for performing it are as follows:
Step 1)
- Execute transaction code ME21N.
- Choose the appropriate purchase order type: in our case NB – standard PO.
- Organizational levels: enter them according to needs.
- Purchase requisition: enter the purchase requisition number released in the previous lesson.
Hit ENTER. You may have to hit ENTER quite a few times to go through several warning messages.
As the screen above shows, the requisition number is entered in the document overview on the left, from where its items are adopted into the order.
Step 2)
- PO quantity: you can see that the PO quantity is rounded down to 2 PAL. That is because we have entered 30pcs on PR, and we have set our order unit to be PAL in our info record, so we have to order in pallets, and system rounds it down.
- Net price: net price field is being populated from purchase info record.
Save the PO and you are finished with converting a purchase requisition into the purchase order.
⚠️ Warning: Check the converted quantity before saving. Rounding into the info record order unit can reduce the ordered amount below the requested demand, as in the example above where 30 pieces became 2 pallets. Correct the quantity on the order item if the shortfall matters.
Bulk Conversion: ME57, ME58 and ME59N
Converting one requisition at a time in ME21N suits ad hoc purchases. A buyer clearing a daily worklist uses one of three collective transactions instead.
| Transaction | What it does | Source required? | Best used for |
|---|---|---|---|
| ME57 | Assign a source of supply, then convert interactively | No, source is assigned in the transaction | Requisitions where the vendor is not yet decided |
| ME58 | Create orders from requisitions that already carry a source | Yes | Daily buyer worklist with known vendors |
| ME59N | Automatic conversion, runs interactively or as a background job | Yes, and it must be unique | High volume repeat procurement with no manual review |
ME59N converts only where exactly one valid source exists and the requisition is flagged as relevant for automatic order creation. Anything ambiguous is skipped and reported, so it never guesses a vendor. Creating an order directly against a source document is covered in creating a purchase order with reference.
Why a Requisition Will Not Convert
Conversion failures almost always trace back to a small set of causes. Work through these before assuming a system fault.
- The requisition is not released. A release strategy applies and at least one release code is still open. Release it in ME54N or collectively in ME55, then retry.
- No source of supply. Source determination found no quota arrangement, source list entry, contract, or info record valid for the delivery date and plant. Create a source list entry or an info record.
- The item is already fully ordered. A requisition item carries an ordered quantity. Once it equals the requested quantity the item no longer appears in the worklist.
- Deletion flag set. An item flagged for deletion in ME52N is excluded from conversion even though the document still exists.
- Closed indicator set. The item was manually closed, which tells SAP no further orders are expected against it.
- Missing purchasing organisation data. The vendor exists but has no data for the purchasing organisation entered, so the order header cannot be built.
After a successful conversion the order continues through goods receipt and invoice verification. Later corrections are made in change purchase order, and the wider process is mapped in the purchasing overview.
