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Custom customer portals

Customer portal development on top of your ERP and CRM

Build a customer portal on your ERP or CRM so customers see orders and documents while the data stays in AFAS, Exact, SAP or Dynamics. Buy a portal product if it covers your process; build custom when it spans systems.

A customer portal lets your customers check their own orders, deliveries, invoices and documents and file requests without calling or emailing. For an IT department the question is not whether that is possible. It is where the data lives, who manages the sign-in and who will still support the portal three years from now. This page answers those three questions.

By Tom Joseph · Last updated: 29 October 2026

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In short

A good customer portal is a window onto your existing systems, not a second database. Orders, stock, contracts and invoices stay in AFAS, Exact, SAP Business One, Dynamics 365 or Salesforce, and the portal reads and writes through their own APIs. Customers sign in through Microsoft Entra ID or their own company account, with roles per contact person. We add AI only where it changes the outcome: questions the portal cannot answer on its own, and search across documents. We build it alongside your IT partner, who then runs it in your own environment.

The first decision

Build or buy: portal products next to custom development

Option	Fits when	Falls short when
AFAS OutSite	Your customer data lives in AFAS Profit and customers mainly view and change their details and exchange documents. OutSite is fully integrated with Profit.	The process also needs data from a WMS, a TMS or a second ledger.
Microsoft Power Pages	You run Dynamics 365 apps on Dataverse. Power Pages builds low-code external websites on the same Dataverse data.	Most of your data sits outside Dataverse, or the portal logic hits the limits of low-code.
Salesforce Experience Cloud	Your service and customer data lives in Salesforce and customers should resolve service questions on their own.	Orders and invoices sit in an ERP that Salesforce does not know about, so you still need an integration.
Custom build	Customers work across several systems, or the portal must do something no product does, such as your own workflow or AI on your documents.	Nobody ends up owning the code. That is why handover and documentation belong in the scope.
SimplyBoost (our own product)	You mainly want to answer general questions from your website, PDFs, FAQ and catalogue on website chat, WhatsApp and Instagram.	The answer has to come from one signed-in customer's order data. That is a custom build.

Architecture

The data stays in your ERP and CRM

The system of record stays in charge. The portal keeps no copy of its own of orders or invoices. It requests them from the source and shows only what belongs to the signed-in customer.
Read and write through the system's own API. For AFAS Profit through GetConnectors and UpdateConnectors, for Exact Online through the REST API per division, for SAP Business One through the Service Layer (OData) and for Dynamics 365 through Dataverse.
Changes pass the source's own validation. An address change or a return request goes to the ERP as a transaction, so the same rules apply as for your inside sales team. AFAS UpdateConnectors are not designed to add large amounts of data in one go, so the design keeps each change small.
A middle layer absorbs limits and outages. ERP APIs cap the number of calls. A small cache for data that rarely changes keeps the portal fast without loading the ERP. More on this in building an API integration.

Sign-in

For consumers and business customers, Microsoft Entra External ID offers a separate external tenant, kept apart from your employees: sign-in with email and password, a one-time passcode or a Google or Facebook account, with multifactor authentication by email or SMS. Partners who want to use their own company account are invited through B2B collaboration and authenticate with their home organisation. Azure AD B2C has not been sold to new customers since 1 May 2025, so a new portal starts on External ID.

Sign-in is half the job. The other half is authorisation: every request checks on the server whether this contact person may see this customer account, this order or this document. OWASP ASVS 5.0 is a useful checklist for those controls and for the security test before go-live. Anyone processing personal data on your behalf records that in a processor agreement under Article 28 GDPR.

AI in the portal

Where AI changes the outcome, and where it does not

Questions no menu covers. Why is this invoice higher than the quote? An AI assistant in the portal reads this customer's order, invoice and agreements and answers with the source attached. When it cannot, the question goes to your inside sales team with the context.
Search across documents. Customers search certificates, delivery notes, manuals and contracts by meaning instead of by file name, within the documents that belong to their account.
Sorting requests. A fault report or return is recognised, completed with the order or serial number and placed in the right queue.
Where AI adds nothing. An order status, an open invoice or a tracking link is an ordinary database query. We do not put a language model in front of it.

Examples by sector

What a customer portal looks like per sector

Example, technical wholesale. Installers see their price agreements, back orders, delivery notes and invoices from Exact or SAP Business One, reorder from earlier orders and find the product sheet or declaration of performance for an article number.
Example, installation and service company. A housing association or owners' association sees maintenance contracts, scheduled visits and completed work orders, and reports a fault with a photo. The report lands as a service order in AFAS or the service management system.
Example, logistics provider. A shipper sees stock per location from the WMS, shipment status from the TMS and the signed CMR or proof of delivery, without customer service looking them up by email.
Example, machine building. A customer sees, per serial number, the delivered configuration, manuals, parts lists and active service agreements from SAP or Dynamics 365, and the assistant finds the answer in the technical documentation of that exact machine.

Working together

Who does what: your IT partner, your IT team and Crux Digits

Area	Your IT team or IT partner	Crux Digits
Hosting and environment	Runs the portal in your own cloud environment, with backups and patches.	Delivers the application with documentation and a runbook for installation.
Identity	Manages the Entra tenant, the multifactor policy and who gets access.	Connects the portal to that tenant and builds the roles per customer and contact person.
ERP and CRM access	Provides an API user with minimal rights and a test company.	Builds and tests the integration, including error handling and limits.
Change process	Approves releases through your change process and DTAP pipeline.	Delivers a changelog, test results and a rollback plan with every release.
After go-live	Monitoring, incidents and first-line questions.	Hands over code, prompts, test set and documentation; further development after that as a separate assignment.

Cost and timeline

What a custom customer portal costs and how long it takes

Step	What you get	Duration	Price (excl. VAT)
AI audit	Processes and systems mapped, build or buy assessed, and a scope with a fixed price for the next step.	1 to 2 weeks	€2,500, credited against the MVP within 60 days
Production-ready MVP	The portal for one customer group and one process, connected to your ERP or CRM, with sign-in and roles, tested with real users.	4 to 6 weeks	€20,000
Production	All customer groups, security testing, monitoring, documentation and handover of all source code to your organisation.	from 8 to 12 weeks	from €50,000
On top	Licences for a portal product or for Entra External ID, plus hosting in your own environment. See our pricing.	ongoing	set by the vendor

Approach

How a customer portal project starts

Do not start with a list of twenty features. Pick one customer group and the one process that costs your inside sales team the most time today: often where a delivery is, a copy of an invoice or the status of a fault. Count the calls and emails about it before the portal goes live, so that after the first months you have a real comparison.

Then comes the next customer group or the next process, on the same integrations and the same sign-in. That keeps every step small enough for your change process, and your IT partner sees how the portal is put together from the first release. One named senior engineer stays from scope to handover. For the wider question of how we build next to existing systems, see custom software development.

FAQ

Frequently asked questions

What does customer portal development cost?

At Crux Digits a custom customer portal costs €20,000 for a Production-ready MVP covering one customer group and one process, and from €50,000 for production with all customer groups, excl. VAT. A €2,500 AI audit up front decides whether a portal product is enough, and that fee is credited against the MVP within 60 days. Licences and hosting come on top.

How long does it take to build a customer portal?

A first working portal for one customer group takes four to six weeks, connected to your ERP or CRM and tested with real users. A full production version with all customer groups, security testing and handover takes from eight to twelve weeks. The timeline depends mostly on how quickly API access and a test environment are available.

Can a customer portal connect to AFAS, Exact or SAP?

Yes, through the system's own API: GetConnectors and UpdateConnectors for AFAS Profit, the REST API for Exact Online and the Service Layer for SAP Business One. The portal reads and writes there directly, so no second set of records appears. If you only run AFAS, look at AFAS OutSite first, which is already integrated with Profit.

Yes. With B2B collaboration in Microsoft Entra External ID, business users sign in with their own organisation's account and the verification that applies there. For customers without such an account, an external tenant offers sign-in with email and password, a one-time passcode or a Google account. Which route fits depends on who your customers are.

What is the difference between a customer portal and an AI chatbot?

A customer portal shows one customer's own data after sign-in: orders, invoices and documents. An AI chatbot answers questions in a conversation. Inside a portal the two work together, with the assistant answering from that signed-in customer's data and documents. A chatbot on the public website, such as SimplyBoost, our own product, answers from general information.

Who runs the customer portal after go-live?

Your IT team or IT partner runs the portal in your own environment and takes care of monitoring and incidents. At handover Crux Digits transfers the source code, prompts, test set and documentation, so you do not depend on us. If you want the portal developed further after that, we do it as a separate assignment at a fixed price.

Which part of your customer contact belongs in a portal?

Tell us which ERP or CRM you run and the three questions your inside sales team gets most. We tell you whether a portal product is enough or which part needs a custom build.

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