Case Study
Custom WooCommerce Shipping Pricing Matrix Plugin
Streamlined a complex shipping pricing setup into a clean WooCommerce plugin featuring 3D volumetric bin packing and precise regional UK surcharge rules.
Project Brief
The client needed a tailored WooCommerce shipping setup capable of handling complex UK freight rules without cluttering their admin dashboard.
We designed and built a clean backend plugin: a smart rate calculator that handles volumetric weight conversions, pallet triggers, regional UK postcode surcharges (Highlands, Islands, NI), and 3D box packing, paired with an intuitive simulator to test live calculations.
The Challenge
Standard WooCommerce shipping treats all GB postcodes the same, forcing merchants to absorb expensive carrier surcharges for deliveries to the Scottish Highlands, Islands, and Northern Ireland.
On top of that, standard weight-only pricing failed for bulky, lightweight items, causing accurate weight readings but drastically undercalculated volumetric freight fees.
We needed to design an effortless UI that handles multi-carrier routing (DPD UK, Royal Mail, Evri, Palletways), automates Brexit and Windsor Framework tax rules, calculates 3D carton fitting, and feels like a natural extension of WordPress.
Functionality
Advanced Rules & Volumetric Engine
Custom volumetric weight formulas ((L x W x H) / 5000), dynamic pallet conversion triggers for oversized items, tail-lift fees, and automatic VAT zero-rating for Channel Islands & Windsor Framework rules.
UK Regional Postcode Matrix
Flexible regional mapping supporting wildcard matching across Scottish Highlands (AB, IV, KW, PA, PH), Scottish Islands (HS, ZE, KA), Northern Ireland (BT), and Isle of Man / Scilly (IM, TR).
3D Bin Packing Algorithm
A custom carton library (Royal Mail Small, Master Cartons, etc.) that virtually packs cart items based on dimensions and payload capacity to calculate true shipping costs.
Live Cart Rate Simulator
An in-admin testing tool that lets staff test shipping calculations in real time by entering postcodes, weights, and cart totals with clear execution logs.
Carrier API & Tax Automation
Integrations for MyDPD API, Royal Mail Click & Drop, Evri Corporate API, and Palletways Grid tables with automated GB-to-BT green lane customs logic.
A closer look
Advanced Rules & Volumetric Surcharges
The core engine control panel. Configures UK volumetric divisors, pallet triggers for oversized freight, tail-lift fees, and automated tax routing for Northern Ireland and the Channel Islands.
UK Postcode Zone Matrix
The regional rule editor. Allows staff to set delivery lead times and per-parcel surcharges mapped directly to UK outward postcode ranges across the Highlands, Islands, and NI.
3D Bin Packing Box Library
The 3D carton management view. Sets up custom box dimensions, container costs, and max payload weights used to calculate item placement and volumetric rates on the fly.
Live Cart Rate Simulator
The interactive test bench. Lets the team test test-run postcodes, weights, and cart values to verify matching rules, packed box results, and live carrier quotes.
Architecture
We engineered the plugin using custom REST API endpoints to skip standard admin-ajax delays during checkout rate calculations. The 3D box packing engine runs as a lightweight PHP service to keep response times under 100ms.
On the interface side, we crafted a clean Tailwind UI that feels modern yet native to WordPress. Carrier APIs fetch live rates seamlessly while dynamic tax handlers adjust Channel Islands VAT and Northern Ireland green lane rules automatically.
Skills Used
Conobe built a custom shipping plugin that completely solved our UK freight headaches. We used to manually swallow hundreds of pounds in unexpected surcharges to the Highlands and Northern Ireland. Now, every order calculates instantly and accurately based on 3D packing and postcodes. The UI is clean, fast, and effortless for our team to manage.
Have a similar project in mind?
Get in touch for a free, no-obligation quote.
Start a Project