Importing Shopify subscribers requires more than transferring addresses and phone numbers. You also need to preserve what each field means, why the contact can receive marketing, and any choice to stop receiving it. Begin with a small sample that includes awkward cases, then reconcile the result before using the imported audience in a campaign.
Prepare the meaning before the format
Inventory email and SMS subscription statuses, exclusions, purchase history, tags, and useful preferences. Keep the original source and appropriate permission evidence available. Do not convert every row to “subscribed” to make the import easier.
Map fields deliberately. Dates, country codes, phone formats, and empty values can behave differently after transfer. A blank field should not become a guessed preference or a default permission. Keep a backup of the original file under appropriate access controls.
Create a mapping sheet before transferring rows
For each source field, record the destination field, expected type, allowed values, blank-value behaviour, and owner. An email subscription status, SMS permission, language preference, and product-interest tag should not all become a generic active flag. Preserve the meaning that will drive later audience decisions.
Write down how conflicting records should be handled. If an older file says subscribed but the current record shows a later unsubscribe, the older value should not simply win because it is in the incoming file. Determine the authoritative source and event history before applying the update. Do not use export time as a substitute for the time of the customer's actual choice.
Keep dates unambiguous and phone formatting appropriate to the destination process. A value such as 03/04 can be interpreted in different ways, and a phone number can lose a leading character when handled as an ordinary spreadsheet number. Inspect the stored result rather than assuming a visually familiar file is correctly typed.
Start with a small sample
Use a representative set containing an active subscriber, an unsubscribed customer, an invalid address, missing optional data, and a record with non-English characters. Inspect the results in Sendvio before importing the full audience.
Confirm that tags and metafields retain their intended meaning and that duplicate records do not produce conflicting statuses. If a mapping is ambiguous, resolve it with the person who owns the source data rather than choosing the most convenient interpretation.
Reconcile the result in layers
Compare the number of input rows, unique matched customer records, newly created records, updated records, rejected or unresolved rows, and marketing-eligible contacts where those counts are available. They answer different questions. Duplicate rows may update one person, and a successfully imported customer may remain correctly excluded from marketing.
For an illustrative 1,000-row file, ending with fewer than 1,000 new records is not automatically a failure. Some rows may match existing customers or contain duplicates. Conversely, a larger sendable audience than expected may indicate that statuses were mapped too broadly. Investigate the difference instead of forcing the totals to match a superficial target.
Verify eligibility before sending
Review the resulting audience count and sample both included and excluded customers. Investigate unexpected growth or shrinkage. Validation helps identify technical contact problems, but it does not establish permission.
Keep imported records separate from the first live campaign until the checks are complete. Sendvio's personal migration support is available on paid plans and can help with the transition. A careful import preserves useful customer history while preventing old data problems from becoming new messages people did not expect.
After the sample succeeds, apply the agreed process to the full import and repeat the relevant checks. Include known excluded records, records with changed preferences, and a few from each source. A successful sample reduces risk but does not prove every row in a larger file is correct.
Keep the original file, mapping version, import result, and unresolved exceptions under appropriate access and retention controls. Resolve exceptions before using the affected records in a campaign. The import is ready when the team can explain both the data that arrived and the audiences it creates, including why some customers remain intentionally outside marketing despite being present in the database.