Every goods receipt, goods issue, and transfer posting in SAP creates an accounting document automatically. SAP knows which G/L account to post to without any manual input from the user. That is automatic account determination, and the entire logic lives in one transaction: OBYC.
What Is Automatic Account Determination?
Automatic account determination is the configuration-based logic that maps a material movement to a specific G/L account in the General Ledger. When a goods receipt against a purchase order is posted, SAP does not ask the user where to post the inventory value or the GR/IR clearing entry. It determines the correct accounts automatically using a chain of configuration values already defined in the system.
This is controlled by OBYC, this is where Finance and MM configuration meet and it requires both teams to be involved when it is configured.
How the Account Determination Logic Works
When a material movement occurs, SAP follows a structured derivation chain to find the correct G/L account:
Example of Transaction Keys in Sourcing and Procurement
What You Must Get Right Before Go-Live
- Every transaction key used in your material movements must have a G/L account assigned, a missing assignment causes a hard error at goods posting.
- Price difference accounts (PRD) must be agreed with Finance before go-live — they affect COGS and inventory variance reporting.
- GBB requires account modifiers, each modifier (BSA, VAX, VBR, VNG, etc.) maps to a different business scenario and needs its own G/L account.