Difference between FS10n ad FBL3n

FBL3N – Display Change Line Items (gives the open item list)
FS10N – Display Acct Balances (gives the balance of transaction figure)

To say it very plain - Transaction FS10N displays balances, this balance could include many different asset numbers, drill down required for individual asset numbers. FBL3N displays detail, drill down not required.

In case you find that balances in the 2 transactions dont match:
1. Line item display was switched on after there had already been postings to the account (Check your master record for changes in FSS4 and see if the line item display was changed at any point. )
2. Archiving has been done (archiving line items but obviously keeping the account balance correct). It can be very time consuming, but you can always use SE16 on table BSEG (with your company code and account number as selection fields) to check the actual line items. Line item display uses one of the index tables (BSIS) and there can be differences between that and the actual document database, which SE16 will show you.
3. Check search criteria of FBL3N
4. Check the G/L account whether it is enabled to Line Item Display
5. Run the programm SAPF190 to check the gap
6. Check for your user role, if you have the complete authorization objects for T Codes FS10N and FBL3N. Please take the help of your Basis Consultant for that.
7. Execute the report TFC_COMPARE_V2 from SE38 and also see the program documentation (blue information button) on the selection screen of the report.
8. Run transaction SE38 and execute program RFSEPA01