A customer portal gives your clients secure access to the information and processes they currently phone or email you about. Order status, documents, registrations, account history, support requests: the things that take up your team's time when handled manually.

We build bespoke portals in .NET, integrated with the systems you already run. Not a product you configure and work around, but a platform built to match how your business actually operates.

16i is a B Corp certified software development agency based in Cheltenham. We have been building portals and business applications for more than twenty years, including a trade portal serving over a thousand installers for a national manufacturer.

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What a bespoke customer portal can do

Every portal is different, because every business handles its customers differently. These are the capabilities we are most often asked for.

Secure client access

Authenticated access to account information, with permissions controlled at the level your business needs rather than the level a product allows

Document exchange

Secure upload, storage and sharing of documents, with version control and a full audit trail of who accessed what and when

Self-service processes

Registrations, applications, claims, bookings and requests handled by the customer directly rather than through your team

Back-office integration

Real-time connection to your ERP, CRM or bespoke systems, so data entered once appears everywhere it is needed.

Reporting and dashboards

Views built for your users and for your internal team, showing the information each actually needs.

Mobile and offline

Companion apps where users work away from a desk, including offline capability where connectivity cannot be relied on.

Grant UK: a portal serving over 1,000 trade installers

Grant UK has been manufacturing heating systems since 1970. Their G1 installer network needed a way to register products, track warranties, manage customer records and receive service reminders, and the process was being handled manually across multiple systems.

We built the G1 portal from the ground up on .NET, integrated directly with Grant's back-office systems so that data entered by an installer flows through in real time with no duplication. A companion iOS and Android app lets installers submit registrations on site, including in rural locations with no data connection, using barcode scanning to capture product serial numbers.

More than a thousand registered installers now use it as part of their working day.

Should you buy portal software or build bespoke?

Off-the-shelf portal products are the right answer more often than a development agency might admit. If your requirements are close to standard, your systems are mainstream, and speed matters more than exact fit, a configurable product will get you working sooner and cheaper.

Bespoke becomes the better option when integration is the hard part, when your workflow is specific to how you operate, when the portal is a significant part of the customer experience, or when licence fees across three to five years would exceed the cost of owning the thing outright.

We are happy to tell you which applies. If an off-the-shelf product fits your requirements, that is what we will say.

Portal projects start with discovery rather than a proposal. We spend time with the people who will use the system and the people who maintain the data behind it, and establish what the portal needs to do before anyone estimates what it will cost.

Integration feasibility is confirmed early rather than assumed. This is the part of a portal project that most often causes difficulty, and we would rather establish exactly what your systems can read and write at the start than discover a constraint after the design is fixed.

For larger builds we usually recommend proving the core workflow with a defined group of users before committing to the full system. It reduces risk substantially and gives you something real to evaluate.

What does a bespoke portal cost?

It depends on scope, and specifically on how many systems the portal has to talk to. As a guide:

  • Portal

    Cost

    Single integration, defined user group, focused workflow

    From £25,000, 8 to 14 weeks

    Multiple integrations, varied user types, complex workflow

    From £60,000, 16 to 24 weeks

    Enterprise platform with multiple environments and phases

    Scoped individually after discovery

These figures assume proper discovery, UX, build, QA and deployment by a professional .NET team. They exclude hosting and ongoing support, which should be included when comparing against a subscription product over three to five years.

  • Our Advantages

    Descriptions

    We have built portals at scale

    Including a trade platform used daily by over a thousand installers, integrated
    with back-office systems and supported by native mobile apps

    No product to protect

    We do not sell portal software, so we have no reason to recommend building when
    buying would serve you better

    Integration is the specialism

    Connecting to proprietary and legacy systems is the part most projects struggle
    with, and the part we do most often

    Long-term relationships

    Most of our client relationships are measured in years. Portals evolve with the
    business and we are set up to support that

    B Corp certified

    Independently assessed on how we treat our people, our clients and our impact

More on customer portals

Working through a portal project? These may help:

Business benefits of customer portals
Customer portal software in 2026
Customer Portal Software vs Bespoke

Talk to us about your portal

If you are considering a customer or client portal, we would welcome a conversation about what is involved. An initial discussion is free and carries no obligation, and if a bespoke build is not the right answer for you we will say so.

Get in touch at hello@16i.co.uk or call +44 (0)1242 654 000.