The quick answer
The error "Account determination for entry ... not possible" means SAP tried to post a goods movement or invoice, needed to find the G/L account automatically, and couldn't — because the account assignment isn't maintained in transaction OBYC for that combination of transaction key (like BSX, WRX or GBB) and valuation class. The fix is to open OBYC, find that transaction key, and enter the missing G/L account for your valuation class. This is the single most common MM posting error, and once you understand the chain below it's straightforward.
Key takeaways
- SAP posts inventory/invoice values to G/L accounts automatically — the config for that is OBYC.
- The account is found from the transaction key + the material's valuation class.
- The error = that combination has no G/L account assigned in OBYC.
- Fix = maintain the missing account in OBYC. Check the material's valuation class and the valuation grouping code too.
What the error means
Every time you receive stock, issue stock, or post an invoice, SAP has to make a financial posting — and it figures out which G/L accounts to use on its own, without you typing them. That automatic lookup is called account determination, and it's configured in OBYC.
The message tells you exactly what SAP couldn't find. Reading the example INT GBB VBR 3000: INT is the chart of accounts, GBB is the transaction key, VBR is the general modification, and 3000 is the valuation class. SAP looked for a G/L account for that exact combination in OBYC, found nothing, and stopped. It's not a bug — it's SAP telling you a piece of configuration is missing.
How account determination works
Understanding this one chain makes every account-determination error solvable. SAP walks from the material to the account like this:
The material carries a valuation class on its accounting view. The movement or invoice uses one or more transaction keys. OBYC holds the table that says "for this transaction key and this valuation class, post to this G/L account." If that row is missing — or the valuation class isn't on the material, or the valuation grouping code isn't set up — the chain breaks and you get the error.
Why it happens
Five things break this chain — the error message points you at which one:
The most common cause. The transaction key + valuation class combination simply has no account maintained. This is what you fix in the steps below.
If the valuation grouping code (valuation modifier) is active, each plant/valuation area must be assigned to one in OMWD, and OBYC must have entries for that code. A missing assignment breaks determination.
If the material's accounting view has no valuation class (common on a half-created or newly extended material), SAP has nothing to look up.
The material type controls which valuation classes are permitted via the account category reference (OMSK). A mismatch can leave the field effectively unusable.
The GBB transaction key splits by general modification (VBR, BSA, VAX and so on). If the specific modification for your movement isn't maintained, you get the error even though other GBB entries exist.
How to fix it, step by step
Read the error and note its parts
Double-click the message for the detail. Note the chart of accounts, transaction key, general modification (if shown), and valuation class — e.g. INT / GBB / VBR / 3000.
Open transaction OBYC
Type OBYC in the command field. You'll see the list of transaction keys (also reachable via OMWB "Configure Automatic Postings").
Select the transaction key from the error
Double-click the key named in the message (e.g. GBB). If prompted, confirm the chart of accounts.
Check the account assignment
Look for a row matching your valuation class (and general modification for GBB, and valuation grouping code if the columns are active). If it's missing or blank, that's your cause.
Maintain the missing G/L account
Enter the correct G/L account (debit/credit as required) for that combination and save. Ask FI which account if you're unsure — this posts real values.
Check valuation grouping & material master
If a valuation grouping code is involved, confirm your plant is assigned in OMWD. Confirm the material's accounting view has the right valuation class (and that it's allowed for the material type in OMSK).
Retry the posting
Repeat the goods movement or invoice. With the account maintained, it posts cleanly.
Transaction keys & FAQ
The transaction keys you'll meet most in OBYC:
| Key | What it posts |
|---|---|
BSX | Inventory / stock posting (the stock value) |
WRX | GR/IR clearing account (goods receipt against a PO) |
GBB | Offsetting entry for goods movements — split by general modification: VBR (consumption), BSA (initial stock), VAX/VAY (goods issue for sales), ZOB (GR without PO) |
PRD | Cost / price differences |
FR1 | Freight / delivery cost clearing |
UMB | Gain / loss from revaluation |
Learn the config behind the errors —
hands-on, on a real SAP system.
VoiSAP's live SAP MM training walks you through OBYC, valuation classes, and account determination on a real system, so errors like this become routine — plus full career support for the Canadian and US market.
*Hands-on training on a live SAP system. Individual outcomes vary.