SDL levy income from SARS file to allocated funding: period imports with validation, per-employer income history, and the statutory splits that fund mandatory and discretionary grants.
How the module fits together end to end. Colours mark who acts: navy = staff/admin, cyan = external user, green = organisation, orange = the system.
From the SARS file to money a grant can be paid from.
Import the SARS SDL file for the period.

Levy income per employer per period, the base for mandatory and discretionary grant funding.

Their SDL history on Levy Income is the record — compare against the SARS file for the period.
This income; grant modules draw on the allocated splits.