Solution : https://service.sap.com/sap/support/notes/987156 (SAP Service marketplace login required)
Key words : 
ableinh meter reading unit               opbel budget billing plan               partner business partner               portion portion               contract contract               vkonto contract account               x_dat_ab, x_duecmp due date               x_lead leading date               x_ledcmp leading date               x_solcmp budget billing request date additional, adjusted               tu 769 budget billing plan & 1, purchases               tu 770 budget billing plan & 1, budget billing request date, budget billing plan &1 due, budget billing request made, tu 333 & 1 budget billing plans, budget billing amount items, leading date
Related Notes : 
       
| 990271 | REUMWS00: Change of the tax amount | 
| 985097 | ABP: Tax determination with due date not possible | 
| 984842 | Change to sales/purchases tax rates in Germany Jan 01, 2007 | 
| 966902 | REUMWS00: No recalculation if partial clearing is reversed | 
| 965447 | REUMWS00: Additional information in the protocol | 
| 943768 | REUMWS00: Taxes on sales/purchases is not recalculated |