B2B Checkout & Regional Payments. NBS IPS QR Instant Payments. ISO 7064 MOD 11-10. Courier Logistics Automation. - Aleksandar Kuzmanovic offers many high-quality services. Standard eCommerce checkouts are designed exclusively for simple retail transactions — they fail completely when handling domestic B2B wholesale procurement requiring legal entity verification, tax ID validation, custom corporate payment slips, and automated courier logistics. Key stats: 0.0s IPS QR generation, 100% Tax ID validation, 9 Slips/A4 Logistics printing, 1,081 SKUs ERP code mapping. Technologies: PHP 8.2, TypeScript, WooCommerce HPOS, Next.js 16, NBS IPS QR API, PostExpress API, Alpine.js, TailwindCSS, ISO 7064 Algorithms, MySQL & PostgreSQL. Contact: aleksandarkuzmanovic02@gmail.com.
B2B Checkout & Regional Payments.
NBS IPS QR Instant Payments. ISO 7064 MOD 11-10. Courier Logistics Automation.
Standard eCommerce checkouts are designed exclusively for simple retail transactions — they fail completely when handling domestic B2B wholesale procurement requiring legal entity verification, tax ID validation, custom corporate payment slips, and automated courier logistics.
I architect and build enterprise-grade B2B and dual-channel checkout systems that eliminate checkout abandonment, guarantee regulatory tax compliance, and automate order fulfillment. By implementing algorithmic tax ID validation (ISO 7064 MOD 11-10 for PIB and Modul 11 for Matični Broj) and native National Bank of Serbia (NBS) IPS QR instant payments, my checkouts turn friction-heavy B2B orders into seamless, instantaneous transactions.
As engineered on the Medical Pharm enterprise platform, this checkout infrastructure features automated 3x3 PostExpress shipping slip generation (printing 9 compliant labels per A4 sheet), real-time bad-debt delivery refusal blacklists cached in-memory with O(1) hash maps, and domestic ERP accounting code mapping for 1,000+ SKUs.
Whether you need to accept regional mobile QR payments, build custom B2B credit-term checkout funnels, or integrate complex enterprise payment gateways, I deliver secure, compliant financial engineering.
Standard eCommerce checkouts are designed exclusively for simple retail transactions — they fail completely when handling domestic B2B wholesale procurement requiring legal entity verification, tax ID validation, custom corporate payment slips, and automated courier logistics.
Services & deliverables.
End-to-end.
Custom Dual B2B/B2C Checkout Funnel
Frictionless, responsive checkout interface with real-time field validation and corporate customer segmentation.
NBS IPS QR Payment Generation Engine
Automated QR code generation adhering strictly to official national bank standards with Obrazac br. 1 rendering.
Algorithmic Tax ID Verification Modules
Client and server-side validation libraries for PIB (ISO 7064 MOD 11-10) and Matični Broj (Modul 11).
3x3 Logistics Label Printing Suite
Automated dispatch management system printing 9 courier-ready PostExpress slips per standard A4 page.
ERP Integration & Reconciliation Exports
Clean CSV/JSON data pipelines mapping store orders to internal ERP accounting code dictionaries.
Why choose my checkout & payment architecture?
NBS IPS QR 3-in-1 Instant Payment Hub
Direct integration with the official National Bank of Serbia IPS QR specification, generating scannable m-banking QR codes and interactive Obrazac br. 1 payment slips instantly upon checkout.
Real-Time Algorithmic PIB & MB Validation
Client and server-side mathematical checksum algorithms (ISO 7064 MOD 11-10 for PIB; Modul 11 for Matični Broj) that reject fake or mistyped business credentials before order submission.
Automated PostExpress 3x3 Logistics Slips
High-precision print stylesheet generating 9 courier shipping slips per A4 page in an exact 3x3 grid, automatically calculating COD (OTKUP) amounts from prepaid orders.
O(1) In-Memory Anti-Fraud Blacklists
Transients-cached hash tables (phones, emails, transliterated names, MD5 address hashes) that detect past delivery refusal risks instantly during checkout with zero SQL table scans.
Dual Customer Segmentation (Retail vs Corporate)
Unified checkout UI that dynamically shifts fields based on customer type, exposing company details and VAT exemption logic only when B2B mode is active.
Domestic ERP Accounting Synchronization
Automated UTF-8 BOM CSV exports mapped to official enterprise accounting codes for seamless one-click imports into Pantheon, Wings, and Saop.
My process.
Simple. Transparent.
Regulatory & Commercial Scoping
We review your corporate sales policies, invoicing rules, accepted payment methods, and logistics contracts.
Validation & Payment Engine Architecture
Configuring the ISO checksum algorithms, NBS IPS QR generation parameters, and anti-fraud hash tables.
Checkout UI & Dynamic Field Engineering
Building responsive dual-tier checkout interfaces with real-time field validation and payment previews.
Logistics & Courier Label Alignment
Formatting high-precision print stylesheets for PostExpress 3x3 label grids and courier dispatch webhooks.
End-to-End Financial Testing
Executing test transactions across all payment methods, verifying bank QR scanning and ERP invoice reconciliation.
Technology Stack
Precision engineering in regional B2B commerce.
Most eCommerce developers approach checkout design as a visual styling exercise. In high-volume B2B commerce, however, checkout is an intricate legal, logistical, and mathematical operation. A single unvalidated tax ID or failed delivery refusal results in manual accounting hours and lost inventory.
When architecting the Medical Pharm platform, our goal was to eliminate all manual fulfillment overhead. By implementing native ISO 7064 MOD 11-10 checksum validation directly into the form fields, invalid company orders are mathematically impossible to submit.
Simultaneously, integrating NBS IPS QR payments provides customers with an immediate 0-fee mobile banking checkout path, while automated 3x3 PostExpress printing turns hours of manual courier slip filling into a one-click print command.
This is the level of deep commercial systems engineering that transforms a basic online store into an automated, high-margin wholesale procurement engine.
Common questions.
Clear answers.
- What is NBS IPS QR and how does it benefit our eCommerce store?
- NBS IPS QR is the National Bank of Serbia instant payment standard. Customers simply scan the QR code displayed on screen or on their invoice using their mobile banking app to execute an immediate, irrevocable transfer. Transaction fees are significantly lower than credit card processing, and funds land directly in your merchant account instantly.
- Why is mathematical PIB validation essential for B2B stores?
- In Serbia, issuing a wholesale B2B invoice with an invalid or mistyped PIB (tax identification number) creates severe tax compliance fines and manual accounting rework. Algorithmic ISO 7064 MOD 11-10 validation mathematically verifies the check digit in real time, preventing invalid orders from being placed.
- Can this checkout system handle cash-on-delivery (COD) surcharges and courier rules?
- Yes. The checkout dynamically applies courier pricing rules, COD surcharges, and generates PostExpress-compliant address slips with automatic differentiation between package weight tiers and collection amounts.
- Does this architecture work with headless Next.js frontends as well as WordPress/WooCommerce?
- Yes. The payment generation, PIB validation, and logistics calculation engines are built as decoupled REST API micro-services that can integrate with modern Next.js frontends or classic WooCommerce HPOS installations.
Ready to start?
Send a message and I'll respond within 24 hours with a clear plan for your project.