Understanding MM FI integration in very simple terms

MM FI integration

When good receipt (GR) and invoice receipt (IR) is performed, accounting document gets generated. Movement of material leads to automatic generation of accounting document and this is referred as MM FI integration.

Question is how system determines which accounts to debit and which accounts to credit?

Let’s understand MM FI integration 

MM FI integration

Movement type:

It’s a three digit number which represents the nature of movement of material.

Movement types are predefined by sap. Depending upon transaction, sap automatically picks the corresponding movement type.

Below shows few examples of movement types:

movement type

Transaction key:

GL account is determined with the help of transaction key.

Below are few examples:

BSX :  Inventory account (helps in determining GL account for inventory)

GBB : inventory offsetting account (helps in determining offsetting GL account of inventory GL account)

WRX : GR/IR clearing account (helps in determining GR/IR clearing account)

PRD : Price difference account (helps in determining GL account for booking any difference in prices)


 Valuation modifier:

Valuation areas are grouped together and this group is known as valuation modifier or valuation grouping code.

Valuation area is basically the level at which material is valued. Material can be valued either at plant level or at company code level. Hence valuation area is either plant or company code.

Consider a scenario; a company code has 3 plants.

If valuation area is set as company code, then the price of material in all 3 plants will be same and material in all 3 plants will be posted to same set of GL accounts.

If valuation area is set as plant, then material price in each plant can be different and material can be maintained using a separate set of GL accounts.

Standard practice is to keep valuation area as plant.

If multiple plants to use the same set of GL accounts, then valuation areas (plants) can be grouped together. GL account to be mapped to this group in OBYC.

Valuation grouping code used in mm fi integration

Benefit of using valuation grouping code or valuation modifier is reduced number of entries to be maintained in OBYC.

Using valuation modifier is optional. Depending upon business requirement it may or may not be used in account determination.


General modifier

General modifier is used only with three transaction keys (GBB, PRD & KON)

General modifier help to post to different GL accounts with the same transaction key.


Valuation class:

Valuation class is used in automatic account determination.

Valuation class is maintained in material master.

valuation class used in MM FI integration


Let's take an example and understand above concept:

From the nature of business transaction, system automatically determines the material movement type involved. 

From movement type, system automatically determines the transaction key and general modifier involved in posting the accounting document.

The material involved in the transaction belongs to a particular plant. From plant, valuation modifier is identified.

From material master, valuation class is identified. (Every material is assigned to a valuation class and this assignment is done in materiel master)

Now system searches for combination of valuation modifier, general modifier, valuation class and mapped GL account. This combination is maintained in T code OBYC.



When goods receipt (GR) is posted against purchase order (PO), System automatically determines that movement type 101 is involved.

From movement type 101, system knows transaction key involved is BSX, WRX & PRD.

From movement type, account modifier if involved is identified.

From plant, valuation modifier is identified.

From material, valuation class is identified.


Below accounting entry is posted:

DR.  Inventory account (GL account mapped under transaction key BSX)

CR.  GR/IR clearing account (GL account mapped under transaction key WRX)

DR/CR.  Price difference account (GL account mapped under transaction key PRD)


Below link to read more on MM-FI integration: