SaaS: Replaced custom billing with Paddle merchant-of-record

The challenge

The team was hand-rolling tax calculations, invoice numbering, and dunning emails. Every quarter, the EU VAT report became someone's full week. Failed-payment retries were inconsistent.

The approach

We migrated active subscribers to Paddle as merchant of record, kept their plan IDs stable, and rebuilt the billing portal on top of Paddle's Subscription API. Webhook handlers cover every lifecycle event end-to-end. We migrated the recurring schedule with a one-time charge alignment so no customer was billed twice.

The result

Quarterly VAT work dropped from a full week to roughly an hour of review. Involuntary churn from failed payments fell from 3.2% to 1.1% in the first 60 days.