VB.NET Developer Required for AI/OCR-Based Purchase Invoice Entry in Existing Billing Software

# Project Title **VB.NET Developer Required for AI/OCR-Based Purchase Invoice Entry in Existing Billing Software** ## 1. Project Overview We are looking for an experienced VB.NET developer with knowledge of OCR (Optical Character Recognition), AI-based invoice data extraction, and SQL Server database integration. We have an existing billing and inventory management software developed using VB.NET and SQL Server. We want to implement a smart purchase entry feature that allows users to upload a supplier purchase invoice as an image or PDF. The system should automatically read the invoice, extract the relevant details, and fill the corresponding purchase entry fields in our existing billing software. The objective is to reduce manual data entry, save time, and minimize billing and inventory entry errors. ## 2. Required Features ### A. Invoice Upload - Add an option to upload or select a purchase invoice from the purchase entry window. - Support PDF files and images such as JPG, JPEG, and PNG. - Allow users to select invoice files from their local computer. ### B. Automatic Invoice Data Extraction The OCR system should identify and extract the following information wherever available on the invoice: - Supplier name - Supplier GSTIN - Supplier invoice number - Invoice date - Purchase order number, if available - Item names - Item codes or barcodes, if available - HSN codes - Quantity - Unit of measurement - Purchase rate - Discount - Taxable amount - GST percentage and GST amount - CGST, SGST, and IGST - Invoice subtotal - Round-off - Total invoice amount ### C. Automatic Item Matching The extracted invoice items should be matched against the existing items in our billing software. For example, if an invoice contains an item name that is slightly different from the name stored in our database, the system should attempt to identify the correct item using available information such as item name, item code, barcode, or HSN code. If an item cannot be matched confidently, it should be highlighted for manual selection rather than automatically selecting an incorrect item. ### D. Automatic Purchase Entry After extracting the invoice information: - Populate the appropriate supplier details. - Fill in the invoice number and date. - Populate the purchase item grid. - Fill in quantities, purchase rates, discounts, and GST details. - Calculate totals and taxes according to the existing software's calculation rules. - Allow the user to review and edit all extracted information. - Provide a confirmation step before saving the purchase entry to the SQL Server database. **Important:** The system must not save an invoice automatically without user confirmation. ### E. Accuracy and Error Handling The implementation should handle: - Clear and scanned PDF invoices. - Photographed invoices. - Different supplier invoice formats. - Multiple items on a single invoice. - Different GST formats. - Poor-quality images where possible. - Unrecognized fields and unmatched products. The system should validate extracted values against invoice totals and flag discrepancies for manual verification. ### F. Internet and Offline Environment Our billing software is installed on a local Windows PC and uses SQL Server. We can provide an internet connection when using the OCR feature. The OCR functionality may use a cloud-based API or another suitable solution, provided it integrates reliably with our existing software. The existing billing software must continue working normally if the internet connection is unavailable. The OCR feature can require an internet connection if necessary. ## 3. Existing Technology - Programming language: VB.NET - Platform: Windows desktop application - Database: Microsoft SQL Server - Existing application: Billing and inventory management software - Integration requirement: Implement the feature inside the existing purchase entry window. The freelancer should have experience working with existing VB.NET desktop applications and SQL Server databases. ## 4. Remote Work Requirements We do not want to share our complete source code or provide a copy of our entire project. The developer must work remotely by connecting to our development PC using UltraViewer, AnyDesk, or another mutually agreed remote desktop tool. We will provide access to the relevant application screens and necessary development environment. The developer must implement and test the feature directly in the authorized development environment. Before starting, we will discuss the technical approach, required access, estimated development time, and project cost. ## 5. Expected Deliverables The freelancer must deliver: 1. A working OCR-based purchase invoice upload feature. 2. Integration with the existing VB.NET purchase entry window. 3. PDF and image invoice processing. 4. Automatic extraction of invoice header and item details. 5. Product matching against the existing SQL Server database. 6. Proper GST and invoice total validation. 7. Manual correction and confirmation before saving. 8. Error handling and user-friendly messages. 9. Testing with multiple real supplier invoices. 10. Documentation explaining the OCR service, API requirements, configuration, and any recurring charges. 11. Details of any third-party OCR services or libraries used. 12. A clear explanation of any future API, subscription, or maintenance costs. All work must be implemented and tested in our development environment before final acceptance. ## 6. Required Developer Experience Please apply only if you have practical experience in at least the relevant areas below: - VB.NET Windows Forms application development. - Microsoft SQL Server integration. - OCR-based document processing. - AI-powered invoice data extraction. - PDF and image processing. - Purchase invoice and inventory management workflows. - API integration with existing desktop applications. - GST invoice data extraction and validation. Experience implementing OCR in billing, accounting, ERP, or inventory so