The verdict in three sentences
A B2B store on PrestaShop 1.6, unmaintained since 2020 and incompatible with PHP 8, exposes the business to known vulnerabilities and module breakdowns at every server update. Two paths exist: an upgrade to PrestaShop 8 or 9 for EUR 15,000 to 25,000 (about USD 16,000 to 27,000), or a new platform for EUR 30,000 to 55,000 (about USD 32,500 to 59,500), both including migration of the 8,000 customer accounts and an SEO redirect plan. The project takes 10 to 16 weeks and usually halves page load time, as a 2026 order of magnitude.
Diagnosis: the cost of standing still
Before choosing, quantify the risk of doing nothing. A PrestaShop 1.6 store with 40 modules piles up technical debt: modules abandoned by their vendors, class overrides that break with every patch, a host forcing a PHP migration.
| Audit point | Typical finding on PrestaShop 1.6 | Consequence | Estimated annual cost |
|---|---|---|---|
| PHP version | PHP 7.1 or 7.2, no security patches | Non-compliant hosting, intrusion risk | EUR 2,000 to 4,000 of special hosting |
| Modules | 40 modules, 12 of them abandoned | Cart bugs, conflicts | EUR 6,000 to 10,000 of fixes |
| Known vulnerabilities | Several published CVEs unpatched | Customer data theft, regulatory fines | Up to 4 % of revenue under GDPR, up to SGD 1 million or 10 % of local turnover under Singapore's PDPA |
| Performance | 4.5 to 6 s load on mobile | Lower conversion | 8 to 15 % of orders lost |
| B2B pricing | Improvised customer groups | Pricing errors, credit notes | 1 to 2 % of web revenue |
| E-invoicing | No structured format (Factur-X, InvoiceNow) | Non-compliance as mandates roll out | Development needed |
For an SME with EUR 2.4 million in web revenue, standing still costs EUR 60,000 to 110,000 a year as an order of magnitude, before any security incident.
Upgrade or new platform
| Criterion | Upgrade to PrestaShop 8/9 | New platform (Sylius, Shopify Plus B2B, custom) |
|---|---|---|
| Budget | EUR 15,000 to 25,000 | EUR 30,000 to 55,000 |
| Timeline | 10 to 12 weeks | 12 to 16 weeks |
| Modules to replace | 25 to 30 of 40, the rest removed | Features rewritten or native |
| Customer pricing and quotes | Possible with paid B2B modules | Native or cleanly built |
| Annual cost | EUR 5,000 to 9,000 | EUR 4,000 to 25,000 depending on licence |
| Team training | Low, familiar interface | Two to three days |
| Lifespan | 4 to 5 years | 6 to 8 years |
The upgrade suits a simple catalogue whose B2B rules fit into customer groups. A new platform pays off as soon as you need customer-specific pricing, quotes, credit limits, a solid ERP connection or clean e-invoicing.
Data migration and SEO
Data migration is the most underestimated item. Customer accounts must be moved with their multiple delivery addresses, order history for reordering, price groups and passwords, reset cleanly with an invitation email. On the SEO side, every old product, category and CMS URL gets a 301 redirect.
| Migrated item | Typical volume | Method | Main risk |
|---|---|---|---|
| Customer accounts | 8,000 | Import script + activation email | Passwords to reset |
| Delivery addresses | 14,000 | Import with deduplication | Incomplete addresses |
| Order history | 60,000 | Read-only import | Inconsistent statuses |
| Products and variants | 3,500 and 12,000 | Cleaned export | Duplicate SKUs |
| URLs to redirect | 5,000 to 7,000 | Tested 301 redirect table | Lost rankings if missed |
Full redirect testing, with a crawl before and after cut-over, limits the organic traffic dip to under 10 % for four to six weeks.
Mini case study
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Thomas, managing director of a packaging supplier near Nantes, generates EUR 2.4 million in web revenue from 8,000 trade accounts. Mobile load time drops from 5.2 s to 2.4 s on the new platform, and conversion rises 12 %, about EUR 288,000 of additional revenue a year. At a 30 % gross margin, that is nearly EUR 86,000. Add EUR 8,000 of avoided module fixes each year: the EUR 42,000 new platform pays back in about six months. The EUR 20,000 upgrade would have paid back faster, but without customer pricing or online quotes, which would have cost about EUR 12,000 to add.
FAQ
How much does replatforming a PrestaShop 1.6 store cost in 2026?
Budget EUR 15,000 to 25,000 for an upgrade to PrestaShop 8 or 9 and EUR 30,000 to 55,000 for a new platform. Data migration and SEO redirects account for 15 to 20 % of the budget.
Can we keep customer accounts and their history?
Yes, the 8,000 accounts, their addresses and orders are imported. Passwords do not always migrate depending on the hashing, so an activation email is sent, with 70 to 85 % reactivation within a month.
Will we lose our search rankings?
With a complete, tested 301 table, the dip stays under 10 % for a few weeks, then traffic often exceeds the original level thanks to speed. Without redirects, the loss can reach 30 to 50 %.
How long will the store be down?
Cut-over usually happens on a Sunday evening with 2 to 4 hours of downtime. Orders placed during the data freeze are re-entered manually.
Which platform should we choose for B2B?
Sylius or a custom build for rich B2B rules and deep ERP integration, Shopify Plus B2B for a simple catalogue with few rules. PrestaShop 9 remains relevant if the team knows the tool and B2B needs are modest.
Let's scope your project. Send us your store URL and module list: we will audit it and quote either an upgrade or a new platform, between EUR 15,000 and 55,000, over 10 to 16 weeks. 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.
