Fix & Extend SAP B1 Integration

I run SAP Business One v10.3 and rely on a C# solution built on the SAP DI API to push sales documents into the system. Two clear jobs now need attention:

Phase 1 – Tip integration correction
Domestic (and eventually export) invoices carry a tip line that the current integration books with VAT, even though the invoice displays that line as exempt. I need an SAP Business Expert who can dive into the C# code, trace the DI API call sequence, and make sure the accounting entry mirrors the invoice: the tip must stay exempt, no VAT should be triggered, and downstream tax reports must remain clean.

Phase 2 – New business unit rollout
A fresh business unit is coming online. Its invoices and credit notes will follow the same structure but post to separate cost centres and accounts. I need the integration extended so these documents land in SAP B1 with the right numbering series and generate balanced journal entries for the new unit.

Key skills I depend on
• Proven experience with SAP Business One v10.3 internals
• Solid C# and SAP DI API work, especially around documents and journal entries
• Sharp troubleshooting abilities to keep us 100 % tax-compliant

Deliverables
1. Updated C# code and deployment package that posts tip lines on domestic invoices as exempt items, with no VAT in the resulting accounting entry.
2. New module (or branch) of the same integration that processes sales documents for the new business unit, producing correct journal entries and respecting its numbering, cost centres and accounts.
3. Brief technical note outlining changes, impacted objects, and any configuration steps needed before go-live.

I can provide the existing Visual Studio solution, DI API credentials and a sandbox company DB for testing. Once these two milestones pass UAT, we will promote to production.