What Is OCI Punchout?

Last updated: August 2026

OCI punchout is a B2B e-procurement integration that connects an external supplier catalog to a buyer’s procurement system via the SAP-specified Open Catalog Interface (OCI). Purchasers jump from their own system straight into the supplier’s web shop, fill the shopping cart there, and hand it back automatically to their procurement system, where approval and ordering take place.

What is a punchout?

A punchout is a catalog access method in electronic purchasing: instead of loading a supplier’s catalog into the procurement system as a file, the buyer “punches out” of the e-procurement system directly into the supplier’s online shop. The shop recognizes the buyer and shows customer-specific assortments, prices and terms. At the end, it is the shopping cart — not the order — that travels back into the procurement system: approval workflows, purchase orders and invoice checks continue to run there as usual. Punchout is the architectural principle; OCI and cXML are the two common protocols that implement it.

What is OCI (Open Catalog Interface)?

OCI stands for Open Catalog Interface — an open catalog interface specified by SAP. It incorporates external product catalogs into SAP procurement applications, so that the data required to create shopping cart items is transferred directly from the external catalog (as the SAP specification puts it). When purchasing teams talk about “an OCI connection”, this is almost always what they mean: the punchout integration of a supplier shop following this SAP standard. Because the specification is openly documented, many e-procurement platforms and B2B shop systems beyond SAP have adopted it — in European B2B purchasing, OCI is the de facto common language for catalog integrations.

How does an OCI punchout work?

Technically, an OCI punchout consists of two steps — an outbound call and a return:

1. Call-up: The procurement system calls the supplier’s catalog URL stored in its configuration, passing parameters such as login credentials, language and the return address (HOOK_URL). The call is a plain HTTP GET or POST. The buyer lands in the shop, already logged in, and sees the negotiated assortment and prices.
2. Return: When the cart is complete, the shop posts the line-item data back to the HOOK_URL through the user’s browser — as an HTML form with standardized fields (NEW_ITEM-DESCRIPTION, NEW_ITEM-QUANTITY, NEW_ITEM-PRICE, NEW_ITEM-MATGROUP and so on). The procurement system creates the shopping cart items from these fields.

Beyond this core flow, the OCI specification defines additional functions that let the procurement system query the catalog without a user session: product detail display (DETAIL), validation of product data (VALIDATE), product search for sourcing (SOURCING) and background search (BACKGROUND_SEARCH).

What is a punchout catalog?

A punchout catalog is the supplier’s web shop in its role as a connected catalog: an online shop reachable from the customer’s e-procurement system via OCI or cXML, serving customer-specific assortments, prices and terms. An example: an industrial company connects its electrical wholesaler’s shop to its SAP procurement system via OCI. The maintenance engineer searches for a circuit breaker in the familiar shop with live availability — but the purchase runs through the employer’s controlled approval process. The supplier maintains one shop; the customer keeps budget and approval control.

What is the difference between a punchout catalog and a static catalog (BMEcat)?

With a static catalog, the supplier delivers product data as a file — in German-speaking markets typically BMEcat — which the customer imports into the procurement system. With punchout, the data stays in the supplier’s shop and is accessed live. Both approaches coexist, and many buying organizations require both:

The last row shows the common denominator: punchout shop or BMEcat file — both are outputs of the same product data foundation. How file-based catalog exchange works is covered in our article on syndication of product data.

What is the difference between OCI and cXML punchout?

OCI and cXML solve the same problem with different origins and mechanics. OCI is the SAP-specified interface: lean, HTML-form-based, widespread in SAP-influenced European procurement. cXML (commerce eXtensible Markup Language) is an XML-based protocol from the Ariba ecosystem, documented at cxml.org and still actively maintained; its punchout is modeled by the PunchOutSetupRequest (call-up) and PunchOutOrderMessage (cart return) messages. cXML dominates in Ariba networks and North America, and beyond punchout it also carries purchase orders, order changes and invoices as XML documents — OCI deliberately stops at the cart handover. For suppliers this means: serving B2B customers across different e-procurement systems usually requires both protocols — ideally fed from one product data source.

What is the current OCI version?

The current specification release is OCI 5.0 (SAP specification document, 2013). Compared to OCI 4.0 it adds four capabilities: replication of catalog data into the SAP system (mass upload via JSON over HTTP(s) or file, enabling cross-catalog search), new fields for transferring item hierarchies, inbound/outbound handlers, and Secure OCI for the secure transfer of user credentials. Note that, per the specification, an OCI 5.0-compliant catalog must also be OCI 4.0-compliant — the classic HTTP punchout mechanics remain the foundation, and many productive integrations still run on the 4.0 feature set.

Which e-procurement systems support OCI?

OCI was specified for SAP’s procurement stack (SRM Server and the catalog interface of SAP ERP applications); current SAP procurement solutions connect external catalogs following the same pattern. Because the specification is openly available, numerous e-procurement platforms and marketplaces — particularly in German-speaking Europe, such as Onventis or Unite/Mercateo — support OCI as well. SAP Ariba natively works with cXML punchout, so suppliers in mixed landscapes regularly encounter both standards. On the supplier side, many B2B shop systems ship an OCI interface as a standard or add-on feature.

What are the benefits of a punchout catalog in B2B sales?

For suppliers, punchout capability is increasingly a market-entry requirement: large customers and public-sector buyers simply mandate OCI or cXML catalog integration in their tenders. Meeting it makes you visible inside the customer’s procurement system — exactly where requesters actually order. Further effects: less maverick buying outside the framework contract, less manual order entry and fewer transcription errors, current prices and availability instead of stale catalog files — and closer customer retention, because an established integration is rarely switched off.

What role does PIM data play in a punchout catalog?

A punchout catalog is only as good as the product data behind it. Three requirements decide whether the integration serves the customer: completeness (the OCI specification formally mandates only description and quantity — in practice, buying organizations also require price, order unit and commodity group per item), classification (many buying organizations require a standardized commodity group per item, frequently ECLASS for e-procurement, so that spend analysis and approval rules work) and freshness across all channels. That is precisely the job of a PIM system: it centrally manages product data, classifications such as ECLASS and ETIM, and customer-specific assortments — and feeds the punchout shop just like BMEcat exports and marketplace feeds. Without this foundation, every punchout integration becomes one-off maintenance.

Where does OCI punchout fit in the PIM/PXM/DAM landscape?

OCI punchout is an output channel — not a data management system. Within the interplay of a PIM system (the leading source for product data and classifications), DAM (media assets) and channel syndication, the punchout catalog sits alongside shop, marketplace and print as one more consumer of the same media-neutral data foundation. The PIM ensures that the shop your customers punch into shows the same current, classified data as every other channel.

OCI punchout with product data from OMN

OMN, the PIM/DAM platform by apollon, is not the punchout interface itself — it is the data foundation behind it. In OMN you maintain product data once, centrally: attributes, media, order-relevant master data and classifications such as ECLASS and ETIM, differentiated per customer or assortment where needed. Via Channel Management you deliver this data to your OCI-capable B2B shop, as BMEcat catalogs or to marketplaces — one data set, many procurement channels, no duplicate maintenance. apollon brings more than 25 years of experience in product data and media processes, particularly in industries where OCI integration is part of the standard requirements catalog. Details: OMN Product Information Management — or talk to us in a free demo about making your catalog data punchout-ready.

FAQ — Frequently asked questions about OCI punchout

How do you set up an OCI punchout?

On the buyer side, the catalog is registered in the procurement system as an external web service: catalog URL plus the parameters documented by the supplier (e.g. access credentials, language). On the supplier side, the shop must accept the OCI call-up and post the cart to the return address. Most coordination effort goes into credentials, assortment activation and a test run per customer.

Which data does the OCI interface transfer?

On call-up: login and control parameters including the return address. On return: standardized fields per cart item such as description, quantity, unit, price, currency, article number and commodity group — plus optional fields for long texts or classification references (OCI 5.0 adds fields for item hierarchies).

Is the OCI specification free?

Yes — the specification is openly documented and freely accessible, which explains its adoption beyond the SAP world. Costs arise from implementing and operating the integration, not from the standard itself.

Is OCI punchout the same as EDI?

No. Punchout covers the catalog and shopping cart phase; EDI (or cXML documents/IDoc) then handles purchase orders, order confirmations, delivery notes and invoices. In many customer projects both belong together: punchout up front, EDI downstream.