Supported source and collections
The reviewed newer Migration centre has an explicit ClientExec reader. This is an export-file reader requiring the matching released core; it is not a live account connector or an automatic database cutover. Select ClientExec and the exact destination storefront.
Native export format: Get Users / Get User JSON export.
Native collections: customers.
Source-specific preparation
Native customer profiles; supply customer_currencies[id] because the public user response omits currency. Use mapped CSV or JSON for packages, invoices, payments and support history; public package endpoints do not document a complete read export.
Export all pages and keep stable source IDs. Remove passwords, password hashes, tokens, saved card/payment instruments and provider credentials. Use a stable source_instance across batches and explicit ISO currency mappings; never infer currency from a symbol or destination default. For collections outside this native reader, choose mapped CSV/JSON and supply every required field explicitly.
Preview and import
Review the complete field and wrapper reference, then upload within the bounded size/row limit. Preview owner, destination, counts, normalised samples, currency mappings and conflicts. Apply only that unchanged reviewed preview with the required sensitive-admin confirmation. An exact repeated source import is idempotent; conflicting changed records are held, not overwritten.
Imported state and limits
New customers start disabled with new random passwords; products stay inactive/manual; automatic service/domain renewal and provider mapping remain off. Historical invoices remain legacy_review and cannot request payment until reconciliation. Historical payments move no funds. Source contacts, ownership, dates and amounts are preserved where supported, while unsupported ticket attachments/messages, orders, credit ledgers, mandates and configuration need separate review. Negative native credit lines are refused instead of silently converted.
Use Migration centre operations for multi-batch parent references, explicit existing-customer mapping, encrypted provenance, transaction/conflict behavior and the guarded CLI. A successful preview is not a production migration acceptance.