Introduction
"How much will my online store cost?" is almost always followed by "well, it depends" — which is true, but not actually useful on its own. This guide breaks that answer down properly: real cost ranges by business type, what specific features actually add to the budget, and the ongoing costs that catch a lot of UK businesses off guard after launch.
If you're still deciding between an off-the-shelf platform and a custom build, our Shopify vs custom e-commerce comparison is worth reading first — this guide assumes you've got a sense of which direction fits, and focuses purely on the numbers.
Cost by Business Type
Rather than a single "e-commerce costs £X" figure, it's more useful to think in terms of what kind of e-commerce business you actually are:
| Business Type | What This Typically Involves | UK Cost Range |
| Single-brand online store | One catalogue, standard checkout, one payment gateway | £5,000 – £8,000 |
| Custom online store with unique features | Custom design, specific integrations, tailored checkout flow | £8,000 – £10,000 |
| Subscription/repeat-order business | Recurring billing, order scheduling, customer account management | £15,000 – £20,000 |
| Multi-vendor or multi-store marketplace | Multiple sellers/stores under one platform, separate inventory per store | £30,000 – £70,000+ |
| Mobile ordering app with POS/hardware integration | Native or cross-platform app, hardware integration (e.g. receipt printers), multiple payment gateways | £35,000 – £80,000+ |
For reference, a platform like DropApp — a multi-store grocery ordering app with dual payment gateways and thermal printer integration — sits in that top tier, since it combines several of the more complex cost drivers at once, not just one.
What Actually Drives Cost (Beyond "How Many Pages")
Number of payment gateways: A single, standard gateway integration (Stripe or Worldpay alone) is relatively straightforward. Supporting multiple gateways, or gateways with different transaction flows (in-person plus online, for example), adds real development time.
Multi-vendor or multi-store logic: This is one of the biggest cost drivers in e-commerce development. Separate inventory, separate order management, and permission structures per seller or store add architectural complexity that affects the whole build, not just one feature.
Hardware or POS integration: Thermal receipt printers, barcode scanners, or in-store card terminals require integration work beyond standard web/app development — and testing this properly, with real hardware, takes real time.
Custom checkout logic: Standard checkout (cart → payment → confirmation) is well understood and relatively quick to build well. Anything non-standard — delivery slot selection, complex discount/voucher logic, split payments — adds cost proportional to how far it strays from the standard flow.
Inventory complexity: A simple product catalogue is straightforward. Real-time inventory sync across multiple stores or sellers, low-stock handling, and variant management (size, colour, weight) all add development time.
Design complexity: A templated design (even a custom one, but following fairly standard e-commerce UX patterns) costs less than a highly bespoke visual design requiring custom illustration, animation, or unusual layout patterns.
Feature-by-Feature Cost Guide
| Feature | Relative Cost Impact | Notes |
| Product catalogue & search | Low–Medium | Cost rises with catalogue size and filtering complexity |
| Standard checkout (one payment gateway) | Low–Medium | Well-understood, relatively quick to implement properly |
| Multiple payment gateways | Medium | Each additional gateway adds integration and testing time |
| Customer accounts & order history | Low | Standard, well-established functionality |
| Multi-vendor/multi-store architecture | High | Affects the whole system's architecture, not just one feature |
| Subscription/recurring billing | Medium–High | Requires careful handling of failed payments, plan changes, cancellations |
| Delivery slot / scheduling logic | Medium | Complexity depends on how flexible the scheduling needs to be |
| POS/hardware integration | Medium–High | Requires testing with real physical hardware, not just software |
| Admin dashboard & reporting | Medium | Often underestimated — your own team needs good tools too, not just customers |
| Mobile app (in addition to website) | High | Effectively a second platform to design, build, and maintain |
Ongoing Costs Most Businesses Underestimate
Payment processing fees — typically around 1.5–2.9% plus a small fixed fee per transaction in the UK, varying by gateway and volume; this is an ongoing operating cost, not a one-off
Hosting and infrastructure — typically £50–£500+/month depending on traffic and complexity, more for high-traffic or multi-store platforms
App/plugin subscriptions — if using Shopify or WooCommerce, these can add up significantly; a custom platform avoids this but has its own maintenance cost instead
Ongoing development and maintenance — budget roughly 15–20% of your initial build cost per year for bug fixes, security updates, and small improvements
Seasonal scaling — e-commerce traffic can spike significantly around sales periods (Black Friday, Christmas); infrastructure needs to handle this, which may mean higher hosting costs during peak periods
How to Keep E-commerce Costs Under Control (Without Cutting the Wrong Corners)
- Launch with your core catalogue and checkout flow working really well, rather than every feature you can imagine — expand based on real customer behaviour once you're live
- Be honest about whether you actually need multi-vendor/multi-store complexity from day one, or whether you could validate the business with a single-store setup first
- Choose payment gateways deliberately, not by default — adding a second gateway "just in case" adds real cost if it's not genuinely needed yet
- Budget for ongoing costs from the start, not just the build — a business that's only budgeted for launch often gets caught off guard by month three
Ready to Scope Your E-commerce Project?
Getting an accurate cost picture starts with being clear on exactly what kind of e-commerce business you're building — a single store, a subscription service, or something closer to a multi-store platform. Our E-commerce Development team can give you a realistic quote based on your actual requirements.
Get in touch to talk through your project, or read our full e-commerce development guide for the broader picture.
