The verdict in three sentences
Adding B2B subscription sales to an e-commerce site costs between EUR 12,000 and 35,000 excl. tax in 2026 (about USD 13,000 to 38,000), depending on plan complexity and integrations. Direct debit (SEPA in Europe, pre-authorized debit in Canada, 0.35 to 0.8% per transaction) should be the default payment method, with cards (1.2 to 1.5%) as a fallback. The stakes go beyond cash flow: well-managed recurring revenue, with churn tracked monthly, is valued 3 to 5 times higher than one-off revenue in a fundraise or sale.
What the setup costs
An office supplies distributor sells products with predictable turnover: paper, toner, coffee, cleaning supplies. It is the ideal subscription profile, provided the site handles variable quantities, adjustments and consolidated invoices.
| Building block | Features | Budget excl. tax |
|---|---|---|
| Plan catalogue | Recurring baskets, frequency, commitment, discount tiers | EUR 2,500 to 6,000 |
| Billing engine | Consolidated monthly invoices, proration, credit notes | EUR 3,000 to 8,000 |
| Recurring payment | Electronic debit mandate, stored card, dunning | EUR 2,500 to 7,000 |
| Customer portal | Modify, pause, switch plan, history | EUR 2,000 to 6,000 |
| ERP and inventory integration | Volume forecasting, stock reservation | EUR 1,500 to 5,000 |
| MRR and churn dashboard | Monthly recurring revenue, cancellations, cohorts | EUR 500 to 3,000 |
| Total, 2026 order of magnitude | EUR 12,000 to 35,000 |
A SaaS billing tool (Stripe Billing, Chargebee, GoCardless with a third-party tool) cuts development but adds 0.5 to 0.8% of billed revenue or a EUR 250 to 600 monthly subscription.
Comparing recurring payment methods
| Payment method | Fee per transaction | Failure rate | Settlement time | Recommended use |
|---|---|---|---|---|
| SEPA Core direct debit | 0.35 to 0.8%, capped at EUR 2 to 5 | 1 to 3% | 3 to 5 days | Default for SME customers |
| SEPA B2B direct debit | 0.5 to 1% | Under 1% | 2 to 3 days | Large accounts, no 8-week refund right |
| Stored card | 1.2 to 1.5% + EUR 0.25 | 5 to 10% | 2 days | Small customers, quick start |
| Bank transfer on invoice | 0% | Frequent delays | 30 to 45 days | Large accounts with purchasing process |
| 30-day terms via factoring | 1.5 to 3% | Risk transferred | Immediate | Long payment-term customers |
SEPA B2B removes the 8-week refund right of SEPA Core but requires the customer's bank to register the mandate; Canadian business PADs follow similar rules. For a EUR 400 monthly basket, the gap between card (EUR 5.05) and SEPA Core (EUR 2) reaches EUR 36 per customer per year.
Tracking churn from month one
A healthy B2B subscription shows monthly churn under 2%. Above 3%, the base turns over too fast for acquisition to stay profitable. Three metrics are enough to start: monthly recurring revenue (MRR), churn by customer count and by revenue, and 12-month net revenue retention, which should exceed 100% thanks to upgrades. The first cancellation signals show 30 to 60 days ahead: lower quantities, pauses, support tickets.
Mini case study
Philippe runs an office supplies distributor serving 600 business customers with an average monthly basket of EUR 400. He invests EUR 24,000 to move 30% of his customers, or 180 accounts, onto subscriptions with direct debit and a 5% discount. The MRR created reaches EUR 68,400 (180 x EUR 380), or EUR 820,800 per year. With direct debit, fees fall to about 0.5%, versus 1.4% by card before, saving about EUR 7,400 per year. Payment reminders drop by 70%, freeing a half-time admin role. With 1.5% monthly churn, he keeps about 83% of subscribers after a year, and his company valuation rises on the recurring share.
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FAQ
What discount should be offered for a subscription?
Between 3 and 8% depending on commitment. Above 10%, the margin on consumables, often 20 to 30%, becomes too thin.
Should an annual commitment be required?
Not at launch: a no-commitment plan with 30 days' notice reassures buyers and converts better. An annual commitment can be offered for 2 to 3 extra discount points.
How are variable monthly quantities handled?
The site offers a base basket editable up to 5 days before each cycle, and the consolidated invoice adjusts automatically. This covers 90% of needs.
Is the setup compatible with e-invoicing mandates?
Yes, as long as the billing engine produces structured invoices. That adds EUR 2,000 to 4,000 if planned from the start.
How long does launch take?
Plan for 8 to 14 weeks, including a 3-week pilot with 20 to 30 volunteer customers before opening to the whole base.
Let's scope your project. Tell us your recurring products, customer count and current billing tool: we will price the subscription and direct debit setup. 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.
