How does a legacy platform's built-in loyalty/rewards module map to Smile.io or LoyaltyLion on Shopify, and what program rules commonly don't survive the switch?

What the import files actually contain

This is the whole surface area, and it is smaller than any migration plan assumes.

Smile's import expects a CSV with an email address and a points value for each customer; the documentation covers point balances and nothing else (per Smile's Help Center, September 2026).

LoyaltyLion's import expects column A email and column B points for Shopify stores, with tier positions supplied in a separate file, and states plainly: "We can't import customers' historic orders. LoyaltyLion will start tracking your customers' order history once you launch the program" (per LoyaltyLion's Help Center, September 2026).

So: balances yes, tiers on LoyaltyLion yes, everything else no.

The program rules that do not survive

1. Earning rules. Points per dollar, category multipliers, bonus events and birthday awards are re-authored in the new app's rule builder. The rules are portable as a concept, not as data.
2. Redemption catalog. Reward tiers, discount values, free-product redemptions and the exchange rate are rebuilt. Check the exchange rate before launch: if 100 points was $5 on the old platform and the new one is configured at $4, you have quietly devalued every balance you just imported.
3. Point expiry. Expiry schedules do not come across, and neither do the accrued clocks. A customer whose points were due to expire in November either keeps them forever or loses them at launch, depending on how you configure the new program. Decide that deliberately.
4. Referral attribution. Who referred whom, and the pending rewards attached, ends at the old platform.
5. Tier anniversary dates. On LoyaltyLion you can place a customer in a tier; the clock that determines when they fall out of it starts fresh.
6. Redemption history. Gone on both. Your support team can no longer answer "what did I redeem last year" from inside the app.

What the two apps cost at mid-market volume

Verified on both App Store listings, September 2026. A $20M to $500M merchant is past every published tier here; both vendors price the real plan by conversation.

Note the overage shape on Smile: $20 per additional 100 orders past 2,500 is $200 for every extra 1,000 orders per month. At 10,000 monthly orders that is a materially different number from the $199 headline, and it is the arithmetic to run before you shortlist.

The sequence that keeps customers whole

1. Freeze earning on the legacy module and announce a short blackout. Two or three days is enough and it is honest.
2. Export balances on the freeze date, not before. Any order that lands between export and cutover creates a balance discrepancy someone will email you about.
3. Reconcile the total points liability against finance's number. Loyalty balances are a balance sheet item, and this is the one moment where the two systems can be tied out exactly.
4. Import balances, then configure rules, then test redemption end to end on a real order.
5. Launch with a communication that states the new exchange rate explicitly, especially if it changed.

When NOT to migrate the balances at all

If the legacy program had no redemption activity to speak of, importing dormant balances imports a liability and an expectation. A clean relaunch with a goodwill grant to active customers is sometimes both cheaper and better received. That is a commercial decision, not a technical one, and it should be made by whoever owns the P&L rather than the migration Gantt chart.