WORDPRESS E-COMMERCE ENGINEERING
Moving 5,000 live SureCart subscriptions without missing a billing date to FluentCart
A SureCart-to-FluentCart cutover for a Swedish subscription business—designed to preserve billing dates, prevent duplicate charges, and expose revenue data that a CSV export could not be trusted to tell us.
~5,000
live subscriptions
6
stage pipeline
20
reconciliation tools
~75
automated tests
| Client | Swedish subscription media business (anonymised) |
|---|---|
| Challenge | Move approximately 5,000 active SEK subscriptions from SureCart to FluentCart without disrupting recurring payments. |
| Delivery | Custom WordPress migration plugin, Stripe recovery tools, FluentCart configuration, live cutover, reconciliation tooling, and operator handover. |
| Stack | WordPress, PHP, SureCart, FluentCart, Stripe API |
| Timeline | Approximately four weeks, May–June 2026 |
The challenge
The client’s revenue depended on recurring card payments. Leaving SureCart meant rebuilding the live billing relationships in Stripe under FluentCart’s control—not simply importing records. Every active subscription needed the same customer identity, price, discount, payment method, and billing date. A mistake could mean a duplicate charge, an unexpected charge on cutover day, or a customer quietly falling out of the revenue flow.
The source exports were not enough to make those calls safely. Subscription statuses could disagree with live Stripe data; payment-method IDs were blank for roughly 20% of customers; and period dates could be distorted by pauses and proration.
What ScalarWP built
ScalarWP built a purpose-made migration plugin with a resumable six-stage pipeline: customers, coupons, subscriptions, Stripe subscriptions, orders, and transaction backfill. Each stage persisted its progress, so a failed run could safely resume rather than start again.
Every Stripe write used a deterministic idempotency key. Re-running a job could not create a second subscription or charge. Before writing data, a pre-flight validator compared the exports, the target store, and live Stripe records, flagging ambiguous records for human review.
We also built a suite of post-cutover repair tools. These recovered missing payment methods from Stripe, reconciled inconsistent payment identifiers, repaired subscription-to-order relationships, backfilled missed renewals, and synchronised records where an export’s apparent status conflicted with the live Stripe state. Tools that could change billing data defaulted to dry-run.
The outcome
- Approximately 5,000 active SEK subscriptions were in scope.
- Eligible subscriptions were recreated with their original billing anchors preserved.
- Stripe-side idempotency protected against duplicate subscriptions and charges.
- Roughly 20% of missing payment methods were recoverable through live Stripe lookup.
- The delivery included about 75 automated tests and 20 focused reconciliation tools.
What ScalarWP delivered
- Resumable migration plugin with a six-stage processing pipeline.
- Pre-flight validation against exports, WordPress, FluentCart, and live Stripe data.
- Deterministic Stripe idempotency to make retries safe.
- Payment-method recovery and post-cutover reconciliation tools.
- FluentCart catalogue configuration, live cutover support, verification, and operator handover.
Why it mattered
A billing migration is not finished when the import completes. The real work is reconciling what the old platform exported, what the new platform expects, and what Stripe is actually doing. By treating the cutover as a controlled engineering operation—not a CSV import—the client could move to a self-hosted commerce stack while protecting the customer experience and their recurring revenue.
Planning a subscription migration?
If your WordPress commerce stack has outgrown its current platform, book a technical review. We’ll map the source data, billing dependencies, edge cases, and a safe cutover path before work begins.
