KOB1 — Actual Line Items on CO Orders and WBS Elements
KOB1 displays actual line items posted to internal orders, WBS elements, or other CO order objects, reading from the CO line item table rather than directly from FI documents. It is the standard tool for tracing why a value landed on an order, reconciling against settlement, and checking budget consumption before period close.
This page covers KOB1, the line item report for CO order objects (internal orders, WBS elements, and similar), including how it differs from the cost center equivalent KSB1, what tables it reads, and the diagnostic categories behind the most common 'the number does not match' complaints. It also covers what changes once the CO line item table is absorbed into the universal journal on S/4HANA.
Reviewed by an ERPClimb SAP consultant on 15 Sept 2026· 1,158 words
What it does
KOB1 lists actual postings on a CO order object: internal order, WBS element, or another object that carries a CO order structure. It is functionally identical to KSB1 (cost center line items) and KSB2 (commitment line items) in report engine terms — same underlying program, different object selection screen. The structural fact that causes most confusion is that KOB1 reads the CO line item table, not the FI document table directly. A value can exist in FI and not yet appear in KOB1 if the posting has not updated Controlling, or it can appear in KOB1 with a different sign, currency, or grouping than the FI document shows, because CO line items carry object currency and controlling area currency values that do not always match the FI document currency one-to-one.
When it is used
KOB1 is reached for whenever someone asks 'why does this order show this cost' or 'where did this posting come from'. It is used during period-end variance review, before running settlement to check what is sitting on an order before it moves, during budget checks when actual consumption looks wrong against KP06 or budget planning, and when reconciling an order balance against the general ledger after a batch posting run. It sits between the originating posting transaction (FB01, FB60, KB21N, MM goods movements) and the settlement or reporting layer. Consultants use it in preference to a Fiori app when they need document-level drill-down with the classic ABAP list toolbar (sort, subtotal, export), rather than a dashboard view of aggregated cost.
How to use it
- Enter the order number, a range, or an order group in the selection screen; alternatively use a WBS element if the report variant supports it
- Set the fiscal year and period (or period range) to be reviewed
- Choose the value type: actual, plan, or commitment; actual is default for tracing real postings
- Optionally restrict by cost element or cost element group to narrow the search
- Execute; the line item list shows document number, posting date, amount, cost element, and offsetting information
- Double-click a line to drill into the CO document, and from there into the originating FI document if one exists
Key fields
- COEP - CO line items: actual, plan, and commitment values by object, cost element, period, and value type; this is what KOB1 actually reads
- COBK - CO document header: links the CO line item to a CO document number and posting date
- AUFK - order master data: order number, status, order type, controlling area, used to resolve the selection and authorization check
- BKPF and BSEG - originating FI document header and line items, reachable only via drill-down from the CO line item, not queried directly by KOB1 itself
How to prove it in the data
In SE16 or SE16N, open COEP filtered on the object number (the order or WBS element internal key, not the external order number typed on screen), fiscal year, and period. Compare the sum of amount fields for the relevant value type against what KOB1 displays for the same selection. If a posting is missing from COEP but visible in BSEG for the same document, the FI-to-CO update did not run or the cost element is not defined as a real cost element. If COEP has the line but KOB1 shows nothing, check the order's status in AUFK for a lock or archiving flag excluding it from the current selection screen.
ECC vs S/4HANA
On S/4HANA, the CO line item table is a compatibility view over the universal journal table, so KOB1 results reconcile automatically with the general ledger line items for the same posting — the historical gap between FI and CO update timing largely disappears. The transaction code itself still works and the selection screen is unchanged. There are Fiori apps that present order or project cost line items with similar filtering, but KOB1 remains the faster tool for ad hoc document-level tracing and export.
Common pitfalls
- Missing line items: a posting confirmed in FI does not appear in KOB1. Check first whether the account is defined as a cost element and cost-relevant; a non-cost-element G/L account never generates a CO line item regardless of the order assignment. Check the value type selected on the KOB1 screen — a commitment or plan posting will not show under actual.
- Amount does not match FI: the CO line item shows a different value than the FI document line. This is normal when the controlling area currency differs from the document currency; compare in the same currency field, not across currency types. Also check whether the order was settled — settlement creates a new CO document that offsets the original line, so the net balance, not the single line, is what should be checked.
- Duplicate-looking entries: the same business transaction appears twice, once from the original posting and once from a repost or transfer posting (KB21N-type entry). This is expected behavior, not an error; the offsetting document number distinguishes the two.
- Authorization or empty result: the user has no authorization for the controlling area or order type, or the order group entered does not resolve to any orders. Check the authorization trace before assuming the data is missing.
- Timeout or long runtime: selection without a period or fiscal year restriction against a wide order group scans the full CO line item table. Always restrict by period range and, where possible, by cost element group before widening the order selection.
Whose problem this is
This is a functional CO problem in the first instance. A good handover states the order or WBS number, fiscal year and period, value type used, and whether the discrepancy is against FI (BSEG) or against a plan or budget figure. Escalate to Basis only if the report times out on a properly restricted selection; escalate to ABAP only if the drill-down to the FI document throws a dump.
Related SAP objects
Reviewed pages this object connects to in the ERPClimb knowledge graph.
Source: ERPClimb — https://erpclimb.com/sap-tcodes/kob1ERPClimb is an independent platform and is not affiliated with SAP SE. Reference pages are written and reviewed by SAP consultants for learning and troubleshooting.