# How to Create a Purchase Order in SAP MM (ME21N) > Source: https://netray.co/erp-help/how-to-create-po-in-sap-mm-me21n > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: ERP Help ## Short answer Create a purchase order in SAP with ME21N: enter the vendor and organisational data in the header, add items with material, quantity, plant and price, and save. A PO can also be created from a requisition through ME21N adopt, ME58 or ME59N. ## Kind how-to ## System sap ## Erp SAP ERP / S/4HANA ## Module MM Purchasing / ME21N ## Query how to create po in sap mm ## Alternate Queries - sap mm order processing - create purchase order ME21N step by step - create purchase order from requisition sap - sap po with account assignment ## Applies To SAP ECC 6.0 and S/4HANA (ME21N); S/4HANA also offers Fiori apps for PO creation ## Steps ### How to create a PO in ME21N **Items:** - Run ME21N. Choose the document type, normally NB (standard PO), from the dropdown. - In the header enter the vendor and, on the Org Data tab, the purchasing organisation, purchasing group and company code. - In the item overview enter material, PO quantity, delivery date, net price and plant. Storage location is optional. - For consumables or services without stock, set an account assignment category, for example K for cost center, and fill the Account Assignment tab. - To copy from a requisition, open the document overview, choose Purchase Requisitions, select the PR and use Adopt. - Check the item conditions on the Conditions tab, then Save. The PO number is assigned. If a release strategy applies, the PO is blocked until released. - Release with ME28 or ME29N, then post the goods receipt in MIGO with movement type 101 referencing the PO. ## Sections ### Creating from a requisition **Body:** Requisitions are created manually in ME51N or by MRP. Buyers then convert them: ME58 creates POs from assigned requisitions, ME59N creates them automatically if sources are assigned, and ME57 assigns sources first. In ME21N you can instead adopt requisition items through the document overview. This is useful when you need to combine several requisitions for the same vendor on one PO. The requisition and PO are linked. After conversion, the PR item shows the PO number, and reports like ME5A reflect the status. ### Account assignment and special items **Body:** Account assignment category decides where the cost goes. K posts to a cost center, A to an asset, F to an internal order and P to a project. For a normal stock material with no account assignment, GR posts to inventory. Item categories change behaviour. Standard is the default, B is limit, L is subcontracting, S is third-party, and D is service. Use them when the process needs special handling, for example subcontracting components. Price comes from the info record if one exists, or from a contract. If no info record exists you enter the net price manually, and you can create the record automatically through the PO item settings. ### The order-to-invoice flow **Body:** - After the PO: goods receipt in MIGO (movement 101), then invoice verification in MIRO. The system compares PO, receipt and invoice in a three-way match. Differences beyond tolerance block the invoice. - If goods receipt is not required, mark the item accordingly and the invoice posts directly. For services, a service entry sheet (ML81N) takes the place of goods receipt. - Changes after creation use ME22N and are tracked in change documents. Display with ME23N. ## Pitfalls - The wrong document type changes number ranges and release strategy. Check it before saving. - A missing info record or price makes the PO value zero and can fail the release check. - Delivery date in the past triggers warnings and blocks MRP's view of the receipt. - A PO with account assignment cannot be changed freely to another category once receipts exist. - If the release strategy applies, buyers often forget to release. See the release strategy page. ## Ai Angle An assistant can draft the PO fields from a requisition or a vendor email, show them for review, and leave the posting to the buyer or to a controlled write-back with human approval. It should never post to SAP on its own. Keeping the model on-prem avoids sending vendor pricing outside the company. ## Faq ### What is the transaction code to create a PO? **Answer:** ME21N creates a purchase order, ME22N changes it and ME23N displays it. ME21N is the current version; the older ME21 is obsolete. ### How do I create a PO from a purchase requisition? **Answer:** Use ME58 or ME59N for conversion in bulk, or adopt requisition items in ME21N through the document overview. ### What is the standard PO document type? **Answer:** NB is the standard purchase order document type. Others cover stock transfers, framework orders and subcontracting. ### Why can I not post a goods receipt for my PO? **Answer:** Usually the PO is still blocked by a release strategy, or the item is flagged as not requiring goods receipt. Check the status in ME23N. ## Search terms how to create po in sap mm, me21n create purchase order, sap mm order processing, sap purchase order from requisition, sap po account assignment, sap ME58 ME59N, sap procure to pay po, sap purchase order tcode --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json