The verdict in three sentences
For a B2B site that generates leads, the mid-tier plan around EUR 350 per month covers the essentials: security, daily backups, 24 h response time and 5 development hours. The EUR 800 plan only makes sense if one hour of downtime costs you more than EUR 500 or if the site carries a regulatory obligation. Whatever the price, three clauses matter more than the rate: exit terms, code ownership and SLA penalties.
Three maintenance plans compared
Here are the three most common retainer levels offered to SMBs and mid-size companies in 2026:
| Service | Essential EUR 120/month | Pro EUR 350/month | Critical EUR 800/month |
|---|---|---|---|
| Security updates (CMS, dependencies) | Monthly | Weekly | Within 24 h of a vulnerability disclosure |
| Backups | Weekly, 4 weeks kept | Daily, 30 days kept | Daily + hourly database, 90 days |
| Uptime monitoring | Every 15 min | Every 5 min | Every minute, SMS alerts |
| Response time on blocking incident | 48 business hours | 24 business hours | 4 h, 7 days a week |
| Included development hours | 2 h | 5 h | 10 h |
| Weekend and holiday on-call | No | No | Yes |
| Monthly report (performance, security, SEO) | No | Yes | Yes + quarterly review |
| Availability commitment | None | 99.5% | 99.9% with penalties |
Unused hours rarely roll over. Negotiate a 3-month rollover at most: most agencies accept it.
What an hour of downtime really costs
Pick the plan based on the cost of an outage, not on the marketing budget. Estimates for three B2B site profiles:
| Site profile | Leads or sales per month | Average value | Estimated cost of one day offline | Matching plan |
|---|---|---|---|---|
| Brochure site, 10 contacts a month | 10 | EUR 2,000 margin | EUR 650 | Essential |
| B2B site, 40 leads a month | 40 | EUR 1,500 margin | EUR 2,000 | Pro |
| Medtech site with healthcare professional portal | 80 + service | EUR 3,000 margin | EUR 8,000 + regulatory risk | Critical |
| B2B e-commerce site, EUR 25,000 a month | 150 orders | EUR 170 | EUR 830 revenue | Pro |
| Client portal with recurring orders | 400 orders | EUR 300 | EUR 4,000 | Critical |
| Corporate site without conversion | 0 | Brand image | Hard to quantify | Essential |
A security breach costs far more than an outage: clean-up EUR 1,500 to 5,000, possible Google deindexing for several weeks, and mandatory GDPR notification to the supervisory authority within 72 h if personal data leaks.
Clauses to negotiate before signing
Exit terms. The contract must require handover within 15 days of all code, credentials, backups and documentation, with no fee beyond 1 to 2 billed transfer days.
Code ownership. Custom code built for you must belong to you. Beware of contracts where the agency keeps the rights to the theme or bespoke modules.
SLA penalties. An availability commitment without penalties commits nobody. The 2026 norm: 5% of the monthly fee per 0.1% below target, capped at 30%.
Need a professional website?
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Term and notice. Prefer 12 months with 1 to 3 months' notice. Refuse 36-month terms with automatic renewal.
Mini case study
Lena, marketing manager at a 60-employee medtech company in Berlin-Adlershof. Her site hosts a portal reserved for healthcare professionals and generates 50 demo requests per month. She compares three quotes: EUR 120, 350 and 800 per month.
In 2025 her site had two outages of 2 days each, due to lack of monitoring. At 50 requests a month, 4 days down means about 7 lost requests. At 1 deal in 5 and EUR 15,000 margin per contract, the estimated loss reaches EUR 21,000. The Critical plan costs EUR 9,600 a year, EUR 5,400 more than Pro. She picks Pro and negotiates an 8 h response time on the professional portal for EUR 450 a month, a compromise at EUR 5,400 a year.
FAQ
Is a maintenance contract mandatory?
No, but a CMS left unpatched for 6 months becomes a frequent target. WordPress sites make up most hacked sites recorded each year, almost always through outdated plugins.
What does one development hour cover?
A complex content change, a new form field or a small page section. A complete new page usually takes 3 to 6 hours.
Can we switch provider mid-contract?
Yes, if the exit clause is well drafted. Allow 1 to 2 weeks of transition and a takeover audit of EUR 500 to 1,500 by the new provider.
Does the plan include hosting?
Rarely at EUR 120. Pro and Critical plans often include it, worth EUR 25 to 120 per month.
Let's scope your project. Send us your site URL and current contract: clause review, a plan matched to your downtime cost and an annual budget. 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.
