If your subscription billing runs on a SaaS platform with a spreadsheet beside it, the platform has stopped fitting. The simple plans go through. Anything outside its defaults (an odd billing cycle, a negotiated price, usage charges, a VAT edge case) becomes manual work for someone in finance.
For many UK businesses the right answer is still a pre-built platform. This page sets out when one is enough, where they break, and what I build when they do. Senior-led: I’m the person you talk to and the person who builds it.
Why off-the-shelf subscription platforms fall short
Stripe Billing, Chargebee, Recurly, Paddle and GoCardless are good products. They suit a business that sells a handful of fixed or tiered plans, takes cards or Direct Debit, and syncs invoices to Xero or QuickBooks. If that’s you, pick one and skip the build.
| Platform | How it charges | Good fit |
|---|---|---|
| Stripe Billing | A percentage of billing volume, on top of card processing | You already take payments through Stripe |
| Chargebee, Recurly | Monthly plans that step up with billing volume | B2B plans with trials, coupons and a customer portal |
| Paddle | A percentage per transaction as merchant of record; it sells on your behalf and handles sales tax | Software sold to customers in many countries |
| GoCardless | A fee per Direct Debit collected | UK customers who prefer bank payments to cards |
They break in predictable places:
- Pricing rules the platform can’t express. Revenue-share splits, commissions, co-terming several contracts onto one renewal date, grandfathered legacy tiers, or a seat price plus metered usage. You end up with manual credit notes and adjustments every cycle.
- Fees that scale with your revenue. Percentage-of-volume pricing is cheap at the start and grows every time you do, with revenue recognition and extra integrations often sold as add-ons.
- Billing that’s out of step with the rest of the business. Subscription changes reach your CRM, accounting package or product by webhook. When a webhook is late or dropped, a cancelled customer keeps access or an upgrade isn’t invoiced, and someone reconciles by hand.
- Lock-in. Your plans, subscription states and billing history live in the vendor’s data model. Leaving means a migration project, so businesses stay on a platform they’ve outgrown.
What we build instead
I start by mapping how you bill today: the plans, the exceptions your team handles by hand, the cycle dates, the integrations and the reports finance rebuilds in Excel. The build encodes those rules directly.
- You pay once for the build and own the code. No percentage of billing volume and no per-seat fee.
- The billing engine follows your pricing: flat-rate, tiered, volume, per-seat, prepaid, usage-based or a mix.
- Payments stay with a PCI-compliant processor (Stripe, GoCardless, PayPal or similar), so card numbers never touch your system.
- Direct API connections to Xero, QuickBooks, Sage, HubSpot or Salesforce, with retries and alerts when a sync fails.
- A full audit log of every invoice, refund, discount and plan change, with who made it and when.
Core features
Subscription lifecycle
- Trials, active, paused, cancelled and expired states, with the rules for moving between them
- Upgrades, downgrades and mid-cycle changes with proration that matches your billing calendar
- Monthly, quarterly, annual or custom intervals, set-up fees, coupons and per-customer price overrides
- Cancellation with a recorded reason
Usage-based pricing
Metering is where pre-built platforms struggle most, because the usage data lives in your product and the platform only sees it through an API. Built in, it works like this:
- Your product records each billable event: an API call, an active user, storage used, a delivery made.
- The system totals events per customer by the rule you choose (count, sum, peak, unique users) for each billing period.
- A rating step applies your tiers, thresholds, included allowances and overage prices, alongside any fixed subscription fee.
- Customers see their running usage in the portal, and you can alert them as they approach a threshold.
- The raw events are kept, so when a customer queries a charge you can show exactly how it was calculated.
Dunning and failed payments
Failed renewals cause churn your customers never chose. Recovering them needs rules, not a single retry:
- Soft card declines (insufficient funds, a temporary block) are retried on a schedule you set. Hard declines (expired, lost or closed card) skip the retries and ask the customer for a new card.
- Card updater services through your processor refresh expired card details before the charge fails.
- When the customer’s bank asks for authentication on an off-session payment, the customer gets an email with a link to confirm it.
- Each stage sends its own message, and you decide when access pauses, when the account goes to a person, and when it’s written off.
- Direct Debit failures come back through Bacs a few days after the collection date, so they follow a separate path from card declines.
- A report shows how much revenue failed, how much came back and at which stage.
Customer self-service portal
- Subscribers view invoices, update payment details, change plan and cancel without emailing you
- Usage to date for metered plans
Revenue reporting
- MRR, ARR, churn, expansion and failed-payment figures from the same data that produces the invoices
- Deferred and recognised revenue schedules for annual and multi-year contracts
- Role-based access so finance, support and management each see what they need
Integrations
- Payments: Stripe, GoCardless, PayPal
- Accounting: Xero, QuickBooks, Sage
- CRM: HubSpot, Salesforce or your own system
- Webhooks out to any other tool you run
UK rules the system has to follow
- VAT and Making Tax Digital. VAT is calculated per invoice by rate and customer location, including reverse charge on B2B cross-border sales, and the records are kept digitally for MTD.
- Consumer subscription rules. The Digital Markets, Competition and Consumers Act 2024 sets up a subscription contracts regime, which the government expects to start in spring 2027: clear information before sign-up, reminders before renewals and at the end of free trials, and cancellation that’s as easy as joining. I build those into the sign-up flow, the reminders and the portal.
- Recurring card payments. A customer can cancel a continuous payment authority with their bank at any time. The system treats that as a cancellation, not a payment to keep retrying.
- Revenue recognition. UK companies reporting under FRS 102 follow a five-step revenue model, close to IFRS 15, from accounting periods starting on or after 1 January 2026. Annual and bundled contracts need deferral schedules your accountant can audit.
- UK GDPR. Role-based access, retention periods and a clean export or deletion route for subscriber data.
How the build works
- First Gear. In five days I build a working prototype of your core billing workflow on your own data, on a private link, plus a one-page build plan with a fixed price.
- First release. Plans, subscriptions, invoicing, one payment processor, the customer portal, dunning and the reports finance needs, live within a month.
- Later phases. Usage metering, revenue recognition, multi-currency and deeper ERP or CRM integration, each a fixed-price phase of about a month.
- Migration and switch-over. I import customers, live subscriptions and invoice history, move card tokens processor to processor, compare totals against the old system, and switch at a billing-cycle boundary.
What it costs compared to SaaS
Most builds cost £2k to £10k and go live within a month, at a fixed price set at the end of First Gear (£495, credited against the build). After launch you get a 30-day fix guarantee and the first month hosted free, then an optional hosting and support plan or you host it yourself.
The comparison that matters is the pricing model. A platform charges every month, and usually a share of what you bill, so the cost rises as you grow. A custom build is a fixed cost plus hosting. If your billing is simple and volume is modest, the platform is cheaper. The build wins when the fees have become a real line item, when your team spends days each month on workarounds, or when a pricing change you want to ship is blocked by what the platform supports.
Industry use cases
- Software and SaaS: seat-based and usage-based pricing, feature access that changes the moment a plan does, trial-to-paid conversion
- Professional services and managed services: retainers with overage on support hours or usage, contract-specific terms and approval before invoicing
- Media and publishing: paywalls, metered article access, gift subscriptions
- Subscription boxes and e-commerce: skip, pause and delivery-frequency changes, linked to stock and fulfilment
- Marketplaces: per-seller pricing rules, commission calculation and payouts
- Property and utilities: service charges, rent collection and consumption-based billing tied to meter readings
Common Questions About Subscription Software for UK Businesses: Pre-Built or Custom
Should I use a pre-built subscription management system or have one built? ›
Start pre-built if you sell a few fixed or simply tiered plans and your finance team isn't keeping a spreadsheet beside the platform. Stripe Billing, Chargebee, Recurly and GoCardless all handle that well. A custom subscription solution earns its cost when your pricing has rules the platform can't express, when its fees grow faster than you do, or when billing has to stay in step with your own product, ERP or member records.
What does a custom subscription system cost? ›
Most builds are £2k to £10k and go live within a month, at a fixed price agreed before the build starts. I begin with First Gear: £495 for a working prototype of your billing workflow on your own data, plus a build plan with that fixed price. Usage metering, revenue recognition and deeper integrations can follow as separate monthly phases, each with its own fixed price.
Can it handle usage-based or hybrid pricing? ›
Yes, and that's the most common reason people come to me. The system records each billable event (an API call, a seat, a gigabyte, a delivery), totals it by the rule you set, then rates it on your tiers or overage terms. A base fee plus metered usage is a normal case. Your customers see their running total before the invoice lands, so the bill isn't a surprise.
How do you recover failed subscription payments? ›
Failed payments get their own rules. A soft card decline is retried on a schedule you choose, and a hard decline triggers a request for a new card instead. Off-session payments that the bank wants authenticated send the customer a link. You decide when access pauses and when someone on your side takes over. Failed Direct Debits arrive days later through Bacs, so they follow a separate path.
Can you move our subscribers off Stripe, Chargebee or Recurly without them re-entering cards? ›
Usually. Card details can move from one PCI-compliant processor to another through a secure token migration, so your customers don't have to do anything. I import customers, live subscriptions and invoice history, check the totals against your old system, and switch over at a billing-cycle boundary so nobody is charged twice or missed.
Which UK rules affect subscription billing? ›
VAT on every invoice, with digital records for Making Tax Digital. UK GDPR for subscriber data. The subscription contract rules in the Digital Markets, Competition and Consumers Act 2024 if you sell to consumers: clear information before sign-up, renewal reminders and cancellation that's as easy as joining. And if you take recurring card payments, your customers can cancel a continuous payment authority with their bank at any time, so your system needs to cope with that.