The verdict in three sentences
For a London HVAC maintenance SME managing 900 contracts, a custom client portal costs 25,000 to 60,000 EUR excluding VAT (roughly 21,000 to 51,000 GBP) and ships in 3 to 4 months. The business case rests on the 300 monthly calls the team handles to send a report or book a visit, about 1.5 full-time staff. A 14-month payback is realistic if the portal plugs into your scheduling system rather than sitting beside it.
What a 25,000, 40,000 or 60,000 EUR portal includes
Price depends less on the number of screens than on integrations. A portal showing PDFs uploaded by hand is cheap. A portal that reads technician schedules, contracts and billing live costs more, and it is the one that removes calls.
| Tier | 2026 budget (ex. VAT) | Scope | Timeline |
|---|---|---|---|
| Essential | 25,000 to 32,000 EUR | Secure login, document area (contracts, reports, invoices), service request form | 10 to 12 weeks |
| Operational | 35,000 to 45,000 EUR | + live job tracking, email and SMS notifications, history per site | 12 to 14 weeks |
| Integrated | 48,000 to 60,000 EUR | + ERP or CMMS sync, e-signature of reports, multi-site and multi-user per client | 14 to 16 weeks |
| Option | 4,000 to 8,000 EUR | Client mobile app (PWA) | + 3 weeks |
| Option | 3,000 to 6,000 EUR | Single sign-on (Microsoft or Google) for key accounts | + 2 weeks |
| Maintenance | 400 to 900 EUR / month | UK or EU hosting, backups, patches, minor changes | Ongoing |
The usual budget drifters in London are well known: migrating old contract data in mixed formats, connecting a CMMS with no documented API, and fine-grained permissions when one client has 15 sites and 40 contacts.
Custom vs SaaS portal: the 3-year comparison
SaaS portals (client modules of CMMS tools or generic products) charge 30 to 80 EUR per user per month. With 900 contracts, even counting one active user in three, the bill climbs fast.
| Criterion | SaaS portal | Custom portal |
|---|---|---|
| Entry cost | 0 to 5,000 EUR setup | 25,000 to 60,000 EUR |
| Recurring cost (300 users) | 9,000 to 24,000 EUR / month list price, 3,000 to 8,000 EUR negotiated | 400 to 900 EUR / month |
| 3-year cost (estimate) | 108,000 to 290,000 EUR | 40,000 to 92,000 EUR |
| Fit with your processes | Limited to settings | Full |
| Branding | Vendor interface | Your brand, your domain |
| Data and code ownership | Vendor | You |
| Lock-in | Annual price rises of 5 to 10 % are common | Supplier can be replaced |
SaaS still makes sense under 50 users or if your field-service software already ships a decent portal. Above 150 users, custom almost always wins on total cost.
The features that actually remove calls
Of the 300 monthly calls at an HVAC maintenance SME, the typical split is: 40 % asking for a visit date, 25 % requesting a report or certificate, 20 % reporting a fault, 15 % about an invoice. The portal should target these four reasons, in that order.
| Call reason | Share | Portal feature | Expected drop |
|---|---|---|---|
| Visit date | 40 % | Visible schedule and automatic D-2 notifications | 70 to 80 % |
| Report or certificate | 25 % | Reports posted automatically after sign-off | 85 to 90 % |
| Fault report | 20 % | Form with photo, priority and acknowledgement | 50 to 60 % |
| Invoice question | 15 % | Invoices and payment schedule online | 40 to 50 % |
Weighted, that is a 65 to 70 % drop in calls, about 200 calls avoided per month.
Mini case study
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Tom, operations director of an HVAC maintenance SME in London, manages 900 contracts and 22 engineers. Two coordinators handle 300 calls a month, 9 minutes each on average including lookups, so 45 hours monthly. He picks an Operational portal at 42,000 EUR plus 700 EUR monthly maintenance.
Gains: 200 calls avoided, so 30 hours a month, valued at 38 EUR fully loaded per hour, give 1,140 EUR a month. Add faster invoicing (reports signed sooner), estimated at 1,800 EUR of cash and chasing saved per month. Net gain: 2,940 EUR minus 700 EUR maintenance, so 2,240 EUR a month. Payback: 42,000 / 2,240, about 19 months, cut to 14 months when counting the retention of 2 key accounts worth 12,000 EUR a year each that required a portal.
FAQ
What is the minimum budget for a serious client portal in London?
Plan on 25,000 EUR (about 21,000 GBP) for a secure portal with documents and service requests. Below 15,000 EUR you usually get a download area with no business logic, which does not remove calls.
How long does it take to launch?
Between 3 and 4 months, including 2 to 3 weeks of scoping. Integration with your CMMS or ERP often takes 30 % of the total timeline.
Is the portal GDPR compliant?
Yes if hosted in the UK or EU, with access logs and per-user permissions under UK GDPR. Budget 2,000 to 4,000 EUR for records, notices and an initial security audit.
Can we start small and extend later?
That is the recommended route: a 25,000 EUR first release focused on documents and scheduling, then a 10,000 to 20,000 EUR second release six months later based on measured usage.
Who owns the code at the end?
You do, if the contract assigns the intellectual property. Also require access to the code repository and technical documentation so you can switch suppliers.
Let's scope your project. We scope your client portal (features, CMMS or ERP integrations, indicative budget of 25,000 to 60,000 EUR, delivery in 3 to 4 months). 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.
