Most UK e-commerce problems aren’t about the storefront. They sit in the gaps between systems. Orders land in Shopify or on Amazon, then someone re-keys them into the warehouse system. Stock counts drift until you oversell something and have to apologise to a customer. Stripe payouts don’t line up with the accounts, so month-end reconciliation eats half a day. The same customer exists three times over, with different details, in your shop, your CRM and your ERP.
E-commerce platform integration is the layer that closes those gaps. It connects your online stores to the back office, ERP, inventory, accounting, shipping and CRM, so data moves automatically instead of by copy and paste.
At ByteGears, we build that layer to fit your operation rather than the other way round. Our UK-based team builds integrations you own outright, with no per-transaction fees, that connect properly to the systems you already run.
Why off-the-shelf e-commerce integration falls short
For a simple setup, off-the-shelf is often the right call. If you’re running one or two channels, standard orders and no unusual approvals, Shopify with Stripe and Xero, glued together with a tool like Zapier, will do the job. We’ll tell you when that’s enough.
The trouble starts as you grow and the standard tools start to push back:
- Per-transaction pricing that punishes growth. iPaaS platforms bill by task, flow or endpoint. Zapier’s task limits bite quickly, and as a store moves from a few hundred orders a month towards thousands, costs can climb from a few hundred pounds a month into the low thousands, for the same work.
- Commodity workflows only. Pre-built connectors assume order in, fulfil, invoice out. They struggle with multi-level approvals, customer-specific pricing tiers, matrix ordering for apparel, drop-shipping or serial-number tracking.
- Legacy systems left out. Older ERPs common in the UK mid-market, like Sage 100 and SYSPRO, often have no pre-built e-commerce connector at all, so you’re paying for a platform that can’t reach your most important system.
- Batch sync, not real time. Many tools sync on a schedule. Stock that updates overnight is stock you can oversell during the day.
- Silent failures. A webhook times out, an order is created in Shopify but never reaches the ERP, and nobody notices until the customer chases. Weak error handling turns into perpetual manual reconciliation.
- Lock-in and price rises. Two years of flows built inside one vendor’s platform is two years you can’t easily leave when the renewal quote jumps.
The result is wasted time, frustrated staff and missed revenue. People build manual workarounds that introduce errors, and software costs climb without the efficiency to match.
How ByteGears does it differently
Our UK-based development approach gives you software that actually works for your business.
Built around your processes
We start by learning how you work now, then build software that supports those workflows instead of fighting them. Your team won’t need weeks of retraining to use a system designed around how they already do things.
Pay once, own it
Swap your monthly SaaS bills for a system you own outright. Custom development needs an upfront investment, but most businesses recover that within 12 to 24 months through the licensing fees they stop paying and the time they stop wasting.
Connects to the rest of your stack
Your storefront should talk to your inventory, accounting, CRM and fulfilment systems without anyone copying data by hand or wrestling with CSV files. We connect to mainstream platforms like Shopify, WooCommerce, Xero, QuickBooks and ShipStation, and we build bridges to the legacy ERPs that pre-built connectors ignore.
Real-time sync that holds up
We use webhooks for real-time updates rather than overnight batches, so stock and orders stay current across every channel. We build in the unglamorous parts that decide whether an integration actually works: idempotency keys to prevent duplicate orders, retry and backoff logic for failed webhooks, and exception queues so a timed-out order surfaces for review instead of disappearing.
UK compliance from the start
We build in UK GDPR, including audit trails of who changed customer data and when, from day one. Where it’s relevant we add MTD-compatible VAT reporting, PCI-safe payment handling through gateways rather than raw card storage, and UK-hosted infrastructure to meet data residency expectations.
Room to grow
We build flexible foundations, so you can add new features, sales channels, or capabilities as your needs change.
Support from people in the UK
Our London-based team answers during UK business hours. From the build through ongoing maintenance, you’re dealing with us, not an offshore team you’ll never speak to.
What we build into your e-commerce integration
We tailor every solution, but these are the kinds of capabilities we deliver:
- Automated order capture that pulls orders from every channel straight into fulfilment and the ERP, with no manual re-keying
- Real-time inventory sync across storefronts and marketplaces, including reserved stock, so you don’t oversell or run out unexpectedly
- Payment reconciliation that matches Stripe and PayPal payouts, fees and settlements against your accounting records
- Customer master data that deduplicates the same buyer across shop, POS, CRM and ERP into one reliable record
- Product and pricing sync, including variants, SKU mapping and customer-specific or volume-based pricing
- Multi-channel listing management, so you publish and update product information across marketplaces from one place
- Returns and reverse logistics handling, with restocking and refund automation
- Approval and routing rules, so high-value or high-risk orders go to a review queue instead of straight through
- A single dashboard pulling order, margin and fulfilment KPIs from every channel into one view
- UK tax handling: VAT calculation and MTD-compatible reporting
- Role-based permissions so staff only see what they need and sensitive data stays protected
- An API-first architecture with webhooks, so future channels and integrations are straightforward to add
How we deliver it
We deliver in phases. A focused Phase 1 gets the highest-value flows live early, then later phases add to a system that’s already earning its keep. That keeps the project moving and avoids the classic mistake of trying to solve everything before launch.
Discovery and planning (2-4 weeks)
We map your systems, your processes and your pain points, and work out what needs to connect to what and which way the data should flow. This is where we agree scope, decide what belongs in Phase 1 and what success looks like.
Phase 1 build (8-12 weeks)
The core usually covers order sync from your main channel into the ERP and fulfilment, stock sync the other way to prevent overselling, payment reconciliation into accounting, and a clean customer import. Our UK-based developers build it with modern tools and check in regularly so you can steer along the way.
Data migration
Migration is often where projects slip. Years of orders, customers and pricing in a legacy ERP, with duplicate records and inconsistent naming, take real effort to clean and reconcile. We treat it as its own workstream and validate the mapping before cutover, so go-live doesn’t turn into a month-end reconciliation scramble.
Testing and go-live (2-4 weeks)
We test against real-world edge cases, the multi-currency orders, split shipments, bundles and discount stacking that pre-built connectors quietly drop, then roll out with as little disruption as possible.
Later phases and support (ongoing)
Once Phase 1 is stable, later work typically adds extra channels, returns automation, advanced reporting, approval workflows or a B2B portal. We provide training and stay available for support afterwards.
Most projects run 3 to 6 months end to end, depending on complexity. We’d rather build something that holds up than rush to hit an artificial deadline.
What the investment looks like
Custom development costs more upfront than signing up for an iPaaS plan. The case for it is the total cost over three to five years, and the fact that it doesn’t get worse as you grow.
The key difference is the pricing model. iPaaS tools bill by transaction or flow, so your integration bill rises every time your business does well. A custom build is a fixed upfront cost plus predictable annual support. For a busy mid-market store, a usage-based platform can run into tens of thousands a year and keep climbing; a custom build with a steady support arrangement often works out lower over a five-year horizon, with no surprises in between.
Worth being honest about the cost drivers, because they’re where estimates move:
- Integration scope. Each additional system means more connectors, mapping and testing.
- Real-time vs batch. Proper real-time sync with robust error handling costs more to build than scheduled jobs, and is usually worth it.
- Compliance. GDPR audit trails, data residency and MTD add meaningful scope where they apply.
- Data migration. Messy legacy data can be a real share of total project cost.
What you get for it: no subscriptions that climb every year, full control with no vendor lock-in, only the features you’ll actually use, and a foundation you can extend rather than rip out and replace.
Every project is different, so we start with a no-obligation consultation to understand what you need, and we’ll say plainly if an off-the-shelf tool would serve you better.
Who this works for
Custom integration earns its place when your operation has logic that templates can’t model. A few patterns we see often:
- Fashion and apparel wholesale. Matrix ordering by size and colour, tiered pricing by trade customer, multi-warehouse fulfilment and lookbook approval flows. Off-the-shelf B2B platforms usually need heavy customisation to handle this; a custom layer over a Shopify storefront is often cheaper.
- B2B distribution. Volume and loyalty pricing tiers, negotiated net-30 and net-60 terms, partial shipments, drop-shipping and warehouse allocation rules. Generic platforms rarely model bespoke pricing and allocation cleanly.
- Food and beverage. Expiry-aware inventory so the oldest stock ships first, local courier integration and traceability logging for food safety audits. Standard platforms don’t track stock by expiry date.
- Luxury goods and jewellery. High-value orders that need AML and KYC screening, risk-scored order approval, VIP pricing tiers and multi-currency handling.
- Subscription and recurring revenue. Tiered subscriptions, gift recipients with alternate addresses, paused billing and credit rollover, the cases standard subscription billing doesn’t cover.
- Multi-channel and omnichannel retail. Unified inventory across Shopify, Amazon, eBay and Etsy, plus customer attribution and margin analysis by channel that usually needs a custom reporting layer on top.
If your setup is simpler, one or two channels and standard orders, an off-the-shelf tool is probably the better answer, and we’ll tell you so. Custom development pays off when generic software can’t handle the way you actually trade.
Common Questions About Custom E-commerce Platform Integration
How does a custom build compare to iPaaS tools like Celigo or Patchworks?
iPaaS platforms are quick to start and fine for standard flows, but they bill by transaction, flow or endpoint. As order volume grows, the monthly cost grows with it, and a fast-growing store can see fees climb from a few hundred pounds a month into the low thousands. A custom build is an upfront investment with predictable annual support, so your costs don't scale with your success. It also handles the bespoke logic templates can't, and you're not exposed to mid-contract price rises or vendor lock-in.
What's the typical development timeline?
A focused Phase 1 covering order sync, stock sync and payment reconciliation usually runs 8 to 12 weeks. Most full projects land in the 3 to 6 month range from discovery to go-live. Legacy ERP migrations with years of messy data, or B2B builds with complex pricing and approvals, can push past that. We give realistic estimates after discovery rather than promising a date we'd have to rush to hit.
Can you integrate with our existing systems?
Yes. We regularly connect storefronts like Shopify, WooCommerce and BigCommerce to accounting tools (Xero, QuickBooks, Sage), ERPs, CRMs, WMS and 3PL platforms such as ShipStation. We also bridge legacy systems with awkward or undocumented APIs, like older Sage or SYSPRO installations, where pre-built connectors simply don't exist. Discovery is where we map every connection point and how data should flow between them.
How do you keep order and inventory data accurate?
We use webhooks for real-time sync rather than overnight batch jobs, so stock levels and orders stay current across channels. Just as important is the error handling: idempotency keys to stop duplicate orders, retry logic for failed webhooks, and exception queues so a silent timeout never means an order quietly goes unfulfilled. We also keep a manual fallback in mind, so a vendor outage doesn't bring your operation to a halt.
What about data security and UK compliance?
We build to UK GDPR, including audit trails that log who accessed or changed customer data and when. Card data is handled through PCI-compliant gateways like Stripe or PayPal, never stored raw. Where you need it, we build MTD-compatible VAT reporting and host data on UK infrastructure to keep you on the right side of UK data residency rules.
What happens after launch?
We provide training materials and hands-on sessions for the teams that use the system day to day, then move into a support arrangement that suits you, from ad-hoc help to a scheduled maintenance plan. Because you own the code, you can extend it as you add channels or change how you sell, with us or with another developer.