1 Introduction
We use BP create WTAX_TYPE ,I don’t find a bapi. We will update for it . We will impement WTax type , WTax code ,Subject in the ‘BP’.

2 implementation
UPDATE lfbw SET witht = gs_alv-witht
wt_withcd = gs_alv-wt_withcd
wt_subjct = gs_alv-wt_subjct
WHERE lifnr = gs_alv-lifnr