TZ21 is a standard SAP Pooled Table which is used to store Control of cost elements for BAV statements data in SAP systems, such as SAP R/3, S/4HANA, depending on the version and release level.
The TZ21 table consists of various fields, each holding specific information or linking keys about Control of cost elements for BAV statements data available in SAP. These include KTOPL (Chart of Accounts), INTRV (Numc3, internal use), FRKSTAR (From cost element), TOKSTAR (To cost element)... See below for full list along with technical details, documentation, text table, check tables, foreign key relationships, conversion routines, relevant tcodes and example ABAP select code etc. .