Services · Ecommerce development · AI chat agent subscription sites
Codeeo builds the commercial side of AI chat agent products for the UK market: the pricing page, sign up and checkout, recurring and usage based billing, VAT invoices and the account area where customers change plans or leave. If you sell an agent by the seat, by the conversation or by resolved ticket, the site has to turn that model into clear prices, correct charges and records your finance team trusts, while meeting UK consumer, payment and data rules.
This page covers the website and billing platform that sells your agent, not the agent itself. Our team works with UK clients remotely, with discovery, design reviews and release sign off held by video call, and the same people stay with the project from scoping through launch and the first billing cycles.
200+ companies servedFrom a first store to an ADX listed developer
What the platform includes
An AI chat agent is an awkward product to price. Customers pay for something that scales with use: conversations handled, messages processed, channels connected, knowledge sources indexed. A flat monthly plan rarely fits, and a pure usage meter frightens buyers who need a predictable budget line. Most vendors settle on a base plan with included volume and a clear overage rate, sometimes with annual commitments for larger accounts.
Whatever model you choose, the website has to explain it in plain English, collect payment in a way UK banks accept, raise VAT invoices that hold up, and let customers move between plans without raising a support ticket. The capabilities below are the ones we scope for most UK launches, in the order a new customer meets them.
Plan cards, comparison tables and a usage estimator that show the total a customer will pay, including any compulsory charges such as onboarding or a minimum seat count. Since April 2025 the Digital Markets, Competition and Consumers Act 2024 treats dripping unavoidable fees into checkout as an unfair practice, so mandatory costs appear in the headline figure.
Buyers see the real total on the first screen they read.
Events from your agent platform, such as conversations started or tickets resolved, flow into the billing system with idempotent keys so nothing is counted twice. Customers watch their allowance in the account area and receive alerts at thresholds you set, before an overage appears on an invoice.
Usage charges customers can check against their own dashboard.
Card checkout through a provider such as Stripe or Adyen, with 3D Secure on the first payment and renewals flagged as merchant initiated so later charges are not declined for missing authentication. Apple Pay and Google Pay sit alongside cards for founders and small teams paying on a company card.
Fewer failed first payments and fewer renewal declines.
Many UK finance teams prefer Bacs Direct Debit or paying against an invoice on agreed terms. We add mandate set up through a provider such as GoCardless, purchase order fields, and an approval step so your sales team can move an enterprise account onto invoiced billing without leaving the platform.
Self serve and sales led customers billed from one system.
The checkout asks whether the buyer is a business, collects a VAT number where relevant, and applies the treatment your accountant confirms for UK, EU and other overseas customers. Invoices carry your VAT registration and company details, and exports suit the Making Tax Digital software your finance team already files with.
Invoices that match what HMRC expects to see.
Upgrades take effect immediately with a prorated charge; downgrades usually wait for the renewal date so customers keep what they paid for. Seat additions, extra channels and add ons such as voice minutes follow the same rules, all written down in discovery so support and finance give the same answer.
Plan changes without a ticket or a manual credit note.
When a renewal fails, the platform retries on a sensible schedule, emails the billing contact with a link to update the card, and shows a banner inside the product. Agent access can drop to a limited mode rather than switching off, so a lapsed card does not silence a customer's support channel overnight.
Involuntary churn handled before it becomes cancellation.
A cancellation route as easy as sign up, renewal reminders, and records of what each customer agreed to. Where you sell to consumers, the Consumer Contracts Regulations add a cancellation window for digital services. We also build so the reminder and exit steps planned under the DMCC subscription rules can be switched on as they commence.
Exit and renewal handling that stands up to scrutiny.
AI agents process customer conversations, so buyers ask hard questions. A trust section holds your data processing agreement, sub processor list, hosting regions, retention policy and model provider details, with a request form for security questionnaires. It shortens procurement for UK firms that answer to the ICO for every processor they appoint.
Procurement teams find answers before they ask.
A back office where support can see a customer's plan, usage and payment history, issue an approved credit, extend a trial period if your product offers one, or pause an account. Finance gets revenue, refunds and VAT summaries by period. Every manual action is logged with the staff member and reason, which auditors and investors both ask to see.
Billing questions answered without engineering help.
Who this is for
The right build depends on how you sell today and who signs off the purchase. A seed stage product selling to small businesses needs a fast, clear checkout. A vendor courting banks, councils or the NHS needs procurement paperwork and invoiced billing more than a slick plan card. Most UK AI chat agent SaaS website development projects sit somewhere between, and often move from one to the other within a year, so we plan the billing model to grow without a rebuild.
Your agent works and early users are on free accounts or manual invoices. We set up the pricing page, the billing provider, VAT handling and a simple account area, keeping the plan structure small enough to change after you see real usage. Product led growth needs a checkout a founder can finish on a phone, so the first release concentrates on that path and on getting the first invoice exactly right.
Start with few plans; usage data tells you where to split them.
Overage is calculated by hand, credit notes are raised in the accounting package and customers email to change seats. We move metering, proration and invoicing into the platform, migrate active subscriptions without double charging, and reconcile the first billing cycle line by line with your finance lead before switching the old process off.
Migration runs in parallel for one cycle before cut over.
Banks, insurers, housing providers and public bodies expect contracts, purchase orders, accessibility statements and security evidence. We build the trust centre, invoiced billing with approval steps, and pages that meet WCAG 2.2 AA so the site itself supports your Equality Act duties. Listing on frameworks such as G-Cloud is a separate commercial step, but the site should be ready for buyers who arrive from one.
Customers in England, Scotland, Wales and Northern Ireland share one VAT system but not always one contract law; Scottish customers fall under Scots law, so your terms may need adjusting. EU and US customers bring different tax and data transfer questions. We structure checkout, terms and invoices so each group sees the right wording, and we flag where your lawyer should review rather than guessing.
How we work together
Most clients begin with a fixed scope build of the pricing, checkout and billing core, priced from the number of plans, billing models, payment methods and integrations involved. After launch, a monthly retainer covers pricing experiments, new add ons and billing changes as your product evolves. Vendors scaling quickly sometimes take a dedicated team that sits inside their own product squad. Every engagement runs remotely with UK clients; the people who scope the work stay on it through delivery.
A defined build with a deadline
We agree what the product has to do, write it down with a price and a date, and build exactly that. Changes are priced before they are made, not discovered on the invoice.
A product that keeps evolving
Named engineers who work your hours, join your standups and stay on the codebase. You direct the backlog; we own the quality of what ships.
Something live that needs looking after
A monthly block of hours for improvements, fixes and the small requests that otherwise wait months. Unused hours carry for a quarter.
Technology
Typically Next.js or Laravel for the site and account area, with Stripe Billing, Chargebee or Paddle for subscriptions, GoCardless for Direct Debit, and connections to Xero, QuickBooks or HubSpot. The choice follows your billing model and the systems your finance and sales teams already run. Hosting region, backups and access controls are agreed with you, and the whole stack sits in accounts registered to your company rather than ours.
01Web
02Commerce
03Data and cloud
04Marketing and tracking
Cost depends on the billing model far more than on page count.
A seat based plan with card payments is the simplest case. Each layer adds work: usage metering from your agent platform, mixed self serve and invoiced customers, Direct Debit, multi currency, EU VAT handling, migration of existing subscribers and integrations with accounting or CRM. We price after discovery, once these choices are written down, and we show which items could move to a later release if budget matters.
Schedule a free consultation and get a written recommendation, with costs, before you commit to anything.
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