What questions should we ask a migration agency specifically about their subscription-migration track record before trusting them with an active subscriber base?

Which questions filter a subscription migration agency fastest?

Three questions about the agency's last three subscription migrations filter fastest, because an agency that has done the work remembers the numbers. Ask them before the cost-benefit case for leaving Recharge or Skio turns into a signed scope, and before anyone touches live billing.

1. "How many active subscribers were on your last three subscription migrations, and to which platforms?" An agency that has done this remembers both. Generic replatform experience is not the same credential.
2. "What payment-method transfer rate did you achieve, and how did you measure it?" The method matters as much as the number, because contracts moved is not payment methods moved. The same rate is the benchmark to write into your own scope.
3. "Where were the cards vaulted on those projects?" Listen for specifics. Shopify migrates customer payment information from four processors, Stripe, Braintree, PayPal Express and Authorize.net, and moving the card numbers themselves needs Shopify Plus or Enterprise (Shopify Help Center, October 2026). Skio says its team cannot move Shop Pay payment methods from one store to another (Skio Help Center, October 2026).

Which questions test how the agency runs the cutover?

Three more questions test the cutover itself, because that is where a subscription migration stops looking like a replatform.

1. "How did you stop the old app billing each contract once it moved?" Shopify strongly recommends pausing billing in the current app while payment methods and contracts migrate, to avoid double-billing (Shopify developer docs, October 2026). So each subscriber bills on one platform at a time, even while both platforms are live. An agency that has done this names the switch-off step and how it checked each contract's first charge on the new platform.
2. "What did you do about contracts created between the export snapshot and cutover?" Listen for a delta sync. Skio, for one, runs a "top-up" migration for holdouts in the old app (Skio's migration overview, October 2026). If the answer is "we paused sign-ups", you have learned the agency's default, and a weeks-long sign-up freeze is rarely the right one.
3. "Who handled the support surge, and for how long?" Agencies that have lived through a subscription cutover talk about this unprompted. Agencies that have not will treat it as your problem.

What should you ask about the agency's failures and references?

Ask what went wrong on the last subscription migration and what it cost to fix, because any agency with three real migrations has a story. An agency with no story has no migrations.

Then ask for a reference from a subscription migration, not a replatform, and ask that reference one question: what surprised you? The answer is almost always a contract field, a gateway constraint or a support volume nobody planned for. Which of the three it was tells you where the agency's blind spot is. Deploi's migration record names the usual gap: vendor imports move contracts, "not dunning state, portal customizations or churn-save rules" (Deploi Build vs. Buy, October 2026). A reference who mentions none of those either ran a simple program or was not close to the work.

What doesn't count as a subscription migration credential?

Platform partner tiers, total projects delivered and the number of Shopify stores launched do not count as a subscription migration credential. None of them shows that an agency has moved live billing relationships. Shopify's own guide says "Credentials are waived for 2026; only commercial activity is evaluated" (Shopify's Q4 2026 tiering guide, October 2026), so a tier measures commercial impact, not subscription work. How Shopify's partner tiers work has the thresholds. Tiers, project counts and store launches are real achievements in a broad discipline, and subscription migration is a narrow one inside it. A store launch can roll back; a billing cutover cannot.

How do you test an agency before you sign?

Test an agency before you sign by asking for a one-page migration runbook, because the runbook shows experience fast. An agency that has done this produces one in a day from a template; one that has not sends a Gantt chart. The runbook should cover export, mapping, delta sync, the old app's billing switch-off, reconciliation and rollback, the lines that belong in the migration's own risk budget. It should also name who fixes data that fails validation. If the destination is Recharge and the agency formats the file, Recharge's third-party policy says "Pre-import data issues / data fixes will be owned by the external team" (Recharge Migration Services, October 2026). Recharge also "does not audit formatting scripts".