A spreadsheet import should help your sales team work from one dependable customer record. If the same people now appear twice in HubSpot, the immediate job is to establish which rows created new contacts, repair confirmed duplicates and correct the matching rule before another upload.
Start with a small sample. A repeated name does not establish that two records represent the same person, and importing a corrected file does not itself consolidate two records that already exist.
This guide covers contact spreadsheet imports. Keep company records, deals and imports of activities outside the first repair unless the evidence shows they are also affected.
Pause the repeat upload and preserve the evidence
Keep the original spreadsheet, the import name and the time it ran. Make a separate working copy for corrections. Ask the person responsible for follow-up to check whether the suspected duplicates have already received calls, emails or tasks, so the clean-up does not leave two colleagues contacting the same customer.
Before editing records, export the relevant properties and retain the affected record links. Treat that export as a reference for checking your work; it is not a complete undo mechanism for every CRM activity or relationship.
Do not delete every record associated with the import. First distinguish records it created from existing records it updated.
Confirm that the import created extra contacts
Open the completed import and compare its new-record and updated-record totals with what you intended. HubSpot’s import troubleshooting guidance explains the summary and downloadable error details. It also warns that row totals do not always equal record totals, so a headline count alone is not proof of duplication.
For each suspected pair, compare the Record IDs, creation dates, email addresses and available history. Two different IDs establish that you are looking at separate records. You still need evidence that they belong to one person.
Check whether the newer record corresponds to a row in the upload and whether its creation timing fits. Record a short explanation for each proposed match: for example, an established customer whose newly supplied address has been confirmed by their account manager. Put uncertain matches aside.
If the suspected records predate the upload, investigate their creation route instead. A spreadsheet repair will not necessarily change the behaviour of a website form or connected integration.
Check which identifier HubSpot actually received
Email matching needs the correct property
For contact imports, HubSpot uses a matching Email value to update an existing contact. If neither Email nor another unique identifier is included, a single-object contact import creates a new contact for each row. These rules are set out in HubSpot’s record deduplication documentation.
Inspect the mapping, not just the spreadsheet header. An address column placed in a custom text property is not the same as mapping it to the contact’s Email property. Names and company names can help a person investigate, but should not be your automatic matching rule.
Also inspect address differences. An unfamiliar personal address or a replacement work address is a reason to investigate identity, rather than assume that HubSpot should recognise the person from their name.
Use HubSpot Record ID for a controlled update
For a batch of existing contacts, export their HubSpot Record IDs and match each correction to the intended record. HubSpot’s import tool guide says a mapped Record ID takes precedence over other mapped unique identifiers.
That makes the matching work consequential. A customer number from another system is not automatically a HubSpot Record ID. Keep external references in their own columns and preserve the HubSpot IDs from the export.
Keep unresolved rows out of the update file. Separate confirmed existing contacts from genuinely new contacts, rather than leaving missing IDs for the import to interpret. When the upload permits creation, a blank Record ID can create another record.
Check secondary email addresses before changing them
HubSpot supports matching an existing contact through a secondary email already stored on that contact. Its import-file requirements explain an important difference: using that secondary address without Record ID preserves the primary email, while including both can replace the primary email with the imported address.
If your correction only concerns a telephone number or job title, avoid adding an email change to the same job. Decide separately which address should remain primary.
Prepare an update-only import
Build the smallest useful file: the confirmed identifier and the properties you deliberately want to change. Leave unrelated ownership, lifecycle and marketing changes out of this repair.
HubSpot’s current single-object import instructions provide an advanced import route with an Update existing records only option. Select Contacts and use that mode when the job should create no contacts.
Review each column mapping. The same instructions provide Don’t import column and Don’t overwrite controls. Use the latter for properties whose existing values you want to preserve; leave it off for a property you intentionally need to correct.
Do not interpret update-only mode as identity checking. It prevents unmatched rows becoming new records, but a wrongly assigned valid ID can still direct your update to the wrong contact.
Give the import a clear name and keep the final file with your change record. Another team member should be able to explain which contacts it targets and which fields it changes.
Repair confirmed duplicates separately
Correcting an identifier prevents future mistakes; it does not merge historical records. Review the existing duplicate pair as a separate task, with the person who understands the customer relationship.
Compare the email to retain, ownership, associated companies and deals, current follow-up and important property values. Do not automatically keep the newest record: the older one may hold the customer history your team needs.
HubSpot’s merge documentation explains how to open the intended primary contact, choose Actions > Merge, select the other record and review the values to retain. Merges combine activities and associations, and cannot be undone through an unmerge action.
Check the account’s merge behaviour before a large clean-up. As checked on 15 October 2026, that documentation distinguishes accounts in the Primary ID Preservation for Merged Records public beta from its documented default behaviour. The beta preserves the primary ID and its active workflow enrolments; the secondary record is unenrolled. Outside that beta, the documentation describes a new resulting ID and both records leaving active workflows.
Verify the resulting ID, connected-system references and any unfinished follow-up after a small repair. Do not restart every workflow simply to restore activity; identify which customer actions remain appropriate.
The separate duplicates manager has subscription requirements: individual review requires Professional or Enterprise, while bulk management requires Data Hub Professional or Enterprise. That is distinct from merging a known pair directly from its records, which requires the relevant merge permissions.
Prove that the next import updates the intended people
Run a small, representative update-only batch before releasing the full file. Choose confirmed matches that exercise the actual repair, including an address exception if one is part of the job. Agree the expected changes first.
- Check the import outcome. The update-only batch should create no contacts. Review unmatched or rejected rows rather than widening the import to create them.
- Open the intended contacts. Confirm the right property changed on the right Record ID. Check an unrelated field that should have been preserved.
- Inspect any exceptions. HubSpot’s import error guidance explains that an update-only error can mean the supplied identifier matches no existing record. Correct the match before retrying affected rows.
- Check the customer handover. Confirm that the responsible colleague can find the right history, deal and next action, without another duplicate task or message.
- Release the remaining update file. Apply the same mappings and retain its summary. Handle genuinely new contacts in their separately reviewed creation batch.
For recurring uploads, make the identifier and mapping part of the handover. Keep an explicit exception list for contacts that cannot be matched confidently. A process that depends on someone remembering to fix the same column every month still needs attention.
Make the repair useful to your sales team
The acceptance test is practical: existing people receive the intended updates, confirmed duplicates retain their useful history, and the next upload does not recreate the problem.
BuzzBoost’s email and CRM service connects customer records with the follow-up your team needs. If imports are creating extra contacts or leaving colleagues unsure whom to contact, talk to BuzzBoost about checking the matching rules, repairing affected records and testing the next upload.
Featured image: AI-generated editorial artwork, not a photograph of a real BuzzBoost office, client or result.
