Why your HubSpot import is failing

HubSpot does not fail an import as one lump. It imports the rows it can and lists the rows it could not, with a reason against each. That list is the useful part, and it is easy to miss.

Open the import from the imports list and download the error file. It gives you the failing rows with the error name attached, which turns a vague failure into a specific fix. Everything below is keyed to those error names.

Worth knowing before you go back to the spreadsheet: some of it can be fixed inside the import tool. At the mapping stage you can replace a value and HubSpot applies the change to every row in that column where it appears, which handles a misspelling repeated across hundreds of rows. That works well for one or two bad values. It stops being the quicker route when several columns need work, or when the same file arrives every month.

These stop the import before a single row is read. They are the quickest to fix and the most common cause of a file that will simply not upload.

These are about the header row and the properties behind it. HubSpot has to turn each of your column names into one of its own properties, and it will tell you when it cannot.

These are the ones that let most of the import through and quietly drop the rest, which is why an import can look successful and still leave you short.

HubSpot matches on a unique identifier, usually email for contacts and domain for companies. Most of these errors mean your file disagrees with itself about which record is which.

This is not really an error, and it catches people out more than the errors do. HubSpot asks whether the import should create records, update them, or both, and it does exactly what you chose.

Create only import means your file matched existing records and HubSpot left them alone, as instructed. Update only import means the opposite: rows that matched nothing were skipped rather than created. If you meant to do both, choose create and update, and run it again.

Some errors are about your HubSpot account rather than your spreadsheet, and no amount of cleaning will move them.

Association errors mean the identifiers linking records to each other are missing, repeated, or too long, and association labels have to exist in HubSpot before an import can use them. Limit exceeded means you have hit your record allowance. GDPR blocklisted email means those contacts cannot be added by import at all, whatever the file says. Those four are HubSpot-side decisions, and the file is not the lever.

Every error above announces itself. The imports that cause real trouble are the ones that succeed. Nothing is rejected, the summary looks healthy, and the damage only surfaces days later when a report is wrong or a rep asks why a contact went cold.

Experienced HubSpot admins consistently name the same handful. An import can overwrite Original Source, which is the field your attribution reporting rests on. It can move Lifecycle Stage, sometimes backwards. It can replace tidy dropdown values with free text typed by whoever built the file. It can break company associations, change record owners and the routing that depends on them, and land values in the wrong property entirely because two columns had similar names.

The one that surprises people most: an import can trigger workflows. If enrollment criteria match the records you just touched, automation fires on all of them at once, and that can mean live emails going out to a few thousand people who were not expecting them.

None of this is difficult. It is the difference between an import you can undo and one you cannot.

Most of the list above comes from three things: a header row that does not match, values that do not match a dropdown, and duplicates. HubSpot lets you patch some of these in the import tool one value at a time, which is fine once. It is the wrong shape when the same export arrives every month, because you are redoing the same corrections by hand each time.

Clean Headers standardizes the header row and removes the blank and duplicate names behind Incorrect number of columns and Property definition not found. Find and Replace collapses the spelling variants behind Invalid enumeration option. Deduplicate removes the repeated identifiers behind Duplicate unique property value. Excel to CSV takes one sheet out of a multi-sheet workbook, which is Invalid sheet count. The CRM Formatter maps your columns onto HubSpot's real property names and shows a preview of what will be created and updated before anything is written.

Dates have two fixes and it is worth knowing both. HubSpot asks you to pick a date format during the import, so choosing the one your file already uses often solves it without touching a cell. When the column itself is inconsistent, which is the harder case, Health Check flags the mixed formats and its Standardize dates fix converts the whole column to YYYY-MM-DD.