The verdict in three sentences
A London subscription business billing 8,000 subscribers with a patchwork of Stripe, spreadsheets and manual chasing typically loses 8 to 12% of revenue to failed payments and late invoices. Chargebee or Recurly solve most of this out of the box for a monthly plan plus 0.5 to 0.75% of billed revenue, while a custom billing platform costs GBP 20,000 to 50,000 as a 2026 estimate and takes 4 to 6 months. Custom only wins when your pricing logic, payment mix or integrations do not fit the SaaS tools, or when the revenue share grows larger than the build cost over 3 years.
What a billing platform has to handle
Recurring billing looks simple until you list the edge cases: proration on plan changes, usage-based components, annual and monthly cycles, VAT at 20% with reverse charge for EU business customers, Direct Debit through Bacs alongside cards, smart retries on failed payments, dunning emails, credit notes, revenue recognition under IFRS 15, and clean exports to Xero or Sage.
| Module | Estimated effort | 2026 cost estimate (GBP) |
|---|---|---|
| Scoping, plans and billing rules | 2 to 3 weeks | 2,000 to 4,000 |
| Customer, contract and plan management | 3 to 5 weeks | 3,500 to 7,500 |
| Recurring billing engine with proration | 4 to 6 weeks | 5,000 to 10,000 |
| Stripe cards + GoCardless Direct Debit integration | 3 to 6 weeks | 3,500 to 10,000 |
| Dunning, smart retries, service suspension | 2 to 4 weeks | 2,500 to 6,500 |
| Customer portal, invoices, payment history | 2 to 4 weeks | 2,000 to 5,000 |
| Finance dashboards, Xero or Sage exports | 2 to 3 weeks | 1,500 to 7,000 |
| Total project | 4 to 6 months | 20,000 to 50,000 |
Custom vs Chargebee vs Recurly
The choice comes down to billed revenue, pricing complexity and how much of your payment mix the SaaS tools cover natively.
| Option | 2026 cost estimate | Direct Debit (Bacs) | Complex usage pricing | Main limitation |
|---|---|---|---|---|
| Chargebee | Plan from about GBP 450 a month + around 0.75% of revenue above threshold | Via GoCardless | Good | Cost scales with revenue |
| Recurly | Plan from about GBP 200 to 700 a month + around 0.5 to 0.9% | Via gateways | Good | Same revenue-share logic |
| Stripe Billing | 0.5 to 0.8% of recurring revenue | Via Stripe Bacs | Good | Tied to Stripe as processor |
| Spreadsheets + manual chasing | 1 to 3 staff | Manual | Poor | High failed-payment losses |
| Custom platform | GBP 20,000 to 50,000 + hosting GBP 120 to 350 a month | Native | Fully tailored | Upfront investment, you own maintenance |
At GBP 280,000 of monthly billing, a 0.75% revenue share is GBP 2,100 a month, about GBP 75,600 over 3 years before plan fees. That is the number to compare with a custom build. Below GBP 100,000 of monthly billing, a SaaS tool almost always wins. Our custom web applications page explains how we approach billing builds, and our SaaS RFP template helps you brief vendors.
Dunning rules that actually reduce churn
Software matters less than the recovery policy it automates. A sequence that works well for UK subscription businesses: card updater and pre-expiry email 14 days before a card expires, smart retries spread over 7 to 10 days, dunning emails on day 1, 3 and 7 with a one-click update link, downgrade or pause on day 10, cancellation on day 21, and instant reactivation once payment succeeds. Moving customers from cards to Direct Debit, which fails far less often, is usually the single biggest lever.
Mini case study
Tom, CFO of a broadband and connectivity provider in London, bills 8,000 subscribers at an average of GBP 35 a month, GBP 280,000 of monthly billing. Failed and late payments cost him 10%, GBP 28,000 a month, and two credit control staff cost GBP 6,000 a month loaded.
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Option A, Chargebee: about GBP 2,100 revenue share plus GBP 600 plan, GBP 2,700 a month, with failed payments expected to drop to 5% (GBP 14,000). Option B, a GBP 45,000 custom platform delivered in 5 months, with GBP 300 hosting and GBP 1,000 maintenance a month, and the same 5% target thanks to Direct Debit migration and retries. Both save GBP 14,000 a month on failed payments; the difference is GBP 2,700 versus GBP 1,300 in running costs. Custom saves GBP 1,400 a month more, so the extra GBP 45,000 pays back against Chargebee in about 32 months. Tom picks Chargebee for now and plans a custom build if billing passes GBP 500,000 a month.
FAQ
How long does a custom billing platform take?
Plan 4 to 6 months including payment provider onboarding and parallel running with your old system. A first release with cards only can go live in about 3 months.
Is Chargebee or Recurly better for UK businesses?
Both support GBP, UK VAT and Direct Debit through partners. Chargebee is often preferred for B2B SaaS, Recurly for consumer subscriptions with high card retry volumes.
What failed-payment rate is realistic?
Between 3 and 6% as a 2026 estimate for a business using smart retries and Direct Debit. Card-only businesses often stay above 7%.
Can a custom platform handle IFRS 15 revenue recognition?
Yes, through deferred revenue schedules exported to your accounting system. This adds 2 to 4 weeks of work and should be validated with your auditor.
Can we suspend service automatically on non-payment?
Yes, via an integration with your provisioning or network system. Reactivation usually happens within 2 minutes of a successful payment.
Let's scope your project. Share your subscriber count, pricing plans and payment methods, and we will scope the priority modules and the go-live 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.
