The verdict in three sentences
A poorly managed B2B e-commerce migration loses 20 to 40% of organic traffic within three months and breaks your business customers' ordering habits. A rigorous plan (audit, 301 redirects, iso-functional rebuild, controlled cutover) caps the loss at under 5% and recovers it in 6 to 10 weeks. Realistic budget: 15,000 to 28,000 EUR, timeline 10 to 16 weeks, with a mandatory rollback plan.
Migration cost line items
A migration is not a redesign. First you reproduce identically, then you improve.
| Line item | 2026 range (EUR) | Role |
|---|---|---|
| Audit + redirect plan | 3,000 - 6,000 | Map URLs, traffic, keywords |
| Catalog / customer / order migration | 8,000 - 18,000 | Data, pricing, history |
| Testing, QA and cutover | 4,000 | Iso-functional, QA, go-live |
| Total | 15,000 - 28,000 | Excluding new features |
The classic mistake: using the migration to change everything. Altering URLs, design and functionality at once makes it impossible to isolate the cause of a traffic drop.
The plan that protects SEO and sales
SEO risk is managed with method, not luck.
| Step | Key action | Impact if neglected |
|---|---|---|
| 301 redirects | 1 old URL = 1 new, never to homepage | -30% traffic |
| Iso-functional | Reproduce existing ordering flows | Business customers lost |
| Metadata preservation | Titles, H1, structured data | Ranking loss |
| Cutover window | Night or weekend, low traffic | Orders lost |
| Rollback ready | Roll back in < 2 h | A day of revenue lost |
| Monitoring D+1 to D+90 | Search Console, logs, sales | Undetected drop |
The redirect plan is the most profitable line item: 1 EUR invested there avoids 10 EUR of lost traffic.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
Mini case study
Julien, e-commerce manager of a B2B auto-parts distributor in Nantes, migrated from Magento 1 to Shopify Plus B2B. Organic traffic: 45,000 visits/month, online GMV 3.2M EUR/year. Migration quote: 22,000 EUR, of which 5,000 for the 4,800-redirect plan. Result: traffic loss capped at 4% the first month, full recovery by week 7. A migration without a plan would have cost, at -30%, roughly 240,000 EUR in annual GMV.
FAQ
How much traffic will I lose? With a solid redirect plan and iso-functional rebuild, under 5% temporarily, recovered in 6 to 10 weeks. Without a plan, 20 to 40% lasting.
Should I migrate all at once or in batches? For B2B, a full cutover in a low-traffic window (night/weekend) with rollback ready beats a gradual migration that doubles the effort.
When do I see the SEO impact? Google re-evaluates in 4 to 12 weeks. Watch Search Console from D+1 and keep old URLs redirected for at least 12 months.
Can I redo everything at the same time? Not recommended. Separate migration (iso-functional) and redesign (improvements) into two phases to isolate the cause of any drops.
How much is rollback? It is included in a serious quote (plan the reverse cutover). Its cost is nil if the migration succeeds, but it saves a day of revenue if blocked.
Let's scope your project. Tell us your current platform, traffic and GMV: we will price the audit, redirect plan and secure cutover. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.