The verdict in three sentences
For a London internet service provider with 9,000 subscribers on full fibre and fixed wireless, businesses and households, a corporate website with a customer portal costs £45,000 to £85,000 in 2026, delivered in 10 weeks. The highest-return module is the postcode availability checker (+£13,000): it answers prospects' first question without tying up customer service. The realistic target for the project is a 25% drop in inbound calls within six months, thanks to the customer portal and online bills.
Why an ISP website must first cut calls
At an ISP this size, the contact centre often handles 6,000 to 9,000 calls a month. Many are simple questions: "can I get fibre in Hackney?", "where is my bill?", "what's my balance?", "why is my line down?". Each of these can be answered online. The website then becomes an operations tool as much as a sales showcase.
The availability checker matches a postcode or address against your fibre and wireless coverage map, then suggests the right plan and a sign-up form. The customer portal shows bills, payment history and line status, and lets customers pay by card or Direct Debit. Business plan pages detail guaranteed speeds, SLAs, static IPs and fix times, which speeds up decisions by IT managers and SME owners.
| Module | Effect on customer service | 2026 price (ballpark) |
|---|---|---|
| Corporate site, 15 to 20 pages (plans, coverage, news) | Inform and sell | £28,000 to £40,000 |
| Postcode availability checker with coverage map | Removes availability calls | +£13,000 |
| Customer portal (PDF bills, history, line status) | Removes billing calls | £17,000 to £25,000 |
| Card and Direct Debit payments | Reduces payment chasing | £6,500 to £10,000 |
| Business plan pages with SLA and quote request | Shortens the B2B cycle | Included |
| Network status and live incidents page | Reduces calls during outages | £3,500 to £5,500 |
| Hosting, monitoring and backups | Portal uptime | £650 to £1,000 per month |
Budget by integration level
The gap between £45,000 and £85,000 depends mainly on the connection to your systems: billing software, subscriber management tool and network monitoring. A portal that reads bills exported every night costs much less than one connected in real time by API.
| Package | Scope | Budget | Timeline |
|---|---|---|---|
| Corporate | Site, plans, static coverage, sign-up form | £45,000 | 6 weeks |
| Corporate + availability | + postcode availability checker | £58,000 | 8 weeks |
| Customer portal | + portal with bills imported nightly | £73,000 | 10 weeks |
| Integrated portal | + payments, real-time line status via API | £85,000 | 12 weeks |
| Ongoing maintenance | Updates, new plans, fixes | £1,700 to £2,800 per month | Ongoing |
The 10-week schedule assumes the coverage map exists in a usable form: a list of postcodes or a geographic file. If it only exists as screenshots, add one to two weeks to structure it.
Calculating the drop in calls
To set the −25% target, classify current calls by reason over two weeks. 2026 ballpark seen at comparable regional ISPs: 30 to 40% of calls concern billing and payment, 15 to 20% availability and plans, 25 to 35% technical incidents. The first two categories are the ones a website absorbs best.
Mini case study
James, sales director of an ISP in London, chooses the Customer portal at £73,000 and £850 a month in hosting, or £10,200 a year. First-year cost: £83,200.
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His contact centre receives 8,000 calls a month at an estimated average cost of £4.50 per call (agent time, telephony, supervision). A 25% drop removes 2,000 calls a month, or £9,000 saved monthly and £108,000 a year. Even with a drop limited to 15%, the £64,800 annual saving pays the site back in about fifteen months, before counting the sign-ups generated by the availability checker.
FAQ
Must the availability checker be accurate to the address?
Not necessarily: a postcode-level check is enough in most cases. Address-level accuracy needs a detailed geographic file and adds about £5,500.
Can the portal connect to our existing billing software?
Yes, either through a nightly file export or through an API if the software offers one. API integration usually adds £9,000 to £16,000 depending on the available documentation.
How do we secure subscriber access?
Login by account number and a code sent by SMS, hashed passwords and access logging, in line with UK GDPR. SMS delivery costs about 3 to 5 pence per message depending on the provider.
Can the site handle business plans on quote?
Yes, each dedicated plan shows guaranteed speed, SLA and fix time, then a form routes the request to the right account manager. A standard business quote is sent within 24 to 48 hours.
How soon do calls go down?
First effects appear 4 to 8 weeks after launch, provided the portal is announced by SMS and email to all subscribers. The −25% target is usually measured at six months.
Let's scope your project. Share your call volume by reason, your coverage map and your billing tool: we will price the site between £45,000 and £85,000 with a 10-week schedule. 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.