How much does a B2B ecommerce platform cost in London in 2026?

The verdict in three sentences

A B2B ecommerce platform is nothing like a consumer store: the expensive parts are per-customer pricing, credit limit management and ERP integration. In 2026 in London, budget 500 to 2,500 EUR/month for a packaged SaaS solution, or 40,000 to 90,000 EUR for an integrated custom build. The return comes from self-service: +20% of orders placed without sales intervention and 2 processing days saved every week.

SaaS vs custom: the real trade-off

The decision is not about the sticker price but about B2B functional depth. A sales director needs per-account price lists, quick reordering by SKU and hierarchical basket approval. Here are the 2026 orders of magnitude seen on the market.

Over three years, an SME with fewer than 800 SKUs often wins with SaaS. Above 2,000 SKUs or with a constraining ERP (Sage X3, SAP Business One), custom becomes cost-effective.

What the budget must cover

A serious quote is not limited to development. Here is the typical split of a 60,000 EUR custom London project.

The two items that most often overrun are ERP integration and the migration of price lists. Precise upfront scoping avoids 20-30% of overspend.

The B2B features that really make the difference

A professional buyer does not have the same expectations as a consumer: they want speed, reliability and their own terms. Here are the most-requested features in 2026 and their weight in the adoption of a London portal.

Quick order by SKU and reorder from history are the two major adoption levers: a buyer who rebuilds their basket in under a minute always returns to the portal rather than calling. Neglecting these two features risks a delivered but little-used portal, so a ROI that never materialises.

Mini case study

Thomas, sales director of an industrial supplies distributor in London, handles 45,000 EUR of monthly orders, 70% of which come by phone or email. Two staff key in orders, about 3,500 EUR/month of cost. With a custom portal at 60,000 EUR, he shifts 60% of orders to self-service: he saves the equivalent of 0.7 FTE, roughly 2,400 EUR/month. Added to the +20% incremental orders (customers ordering evenings and weekends), the portal pays back in about 20 months, then generates a recurring net margin.

FAQ

What minimum budget starts a credible B2B ecommerce in 2026? Budget at least 6,000 EUR/year in SaaS for a solution with per-customer pricing and buyer accounts. Below that, you get a repurposed consumer store with no credit management.

How long for a custom portal? Between 4 and 8 months depending on ERP complexity. Real-time stock and pricing integration alone accounts for 6 to 10 weeks of work.

Does self-service really cut sales workload? Yes: on 2026 projects we see +20% orders placed without intervention and a 2-day/week drop in admin processing, freeing reps for prospecting.

Should you integrate online payment in B2B? Not always: 65-70% of B2B transactions stay on account with 30-day terms. The portal then manages the credit limit and automatic blocking above the ceiling.

Can you migrate later from SaaS to custom? Yes, but budget 8,000 to 20,000 EUR for catalogue and customer migration. Better to anticipate the 2,000-SKU tipping point.

Let's scope your project. Tell us your catalogue, your ERP and your monthly order volume: we cost SaaS vs custom. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.