HubSpot imports a .csv, .xlsx or .xls file with one sheet, a header row whose column names match HubSpot properties, fewer than 1,000 columns, and UTF-8 encoding if the data has non-English characters. Each row then has to follow HubSpot’s format rules for dates, phone numbers, checkboxes and dropdown values, and new contacts need an email address column. If your file comes from another CRM, a form tool or a spreadsheet that several people edit, CSVPrune from Automata Labs can fix the encoding, trim and standardize values, and remove duplicates on your PC before you upload anything.
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What file format does HubSpot require for imports?
HubSpot’s knowledge base article Format import files, last updated 11 September 2026 when we checked it, says all import files must:
- “Be a .csv, .xlsx, or .xls file.”
- “Contain only one sheet.”
- “Include a header row in which each column header corresponds to a property in HubSpot.” The columns can be in any order.
- “Contain fewer than 1,000 columns.”
- “Be UTF-8 encoded if the file includes foreign language characters.”
For Excel files, the data must also stay within Excel’s own worksheet limits, and date and time picker columns must use Number format cells.
The header row is where most first imports go wrong. If a column is called “E-mail Address” in your export and “Email” in HubSpot, you will have to map it by hand during the import. Renaming headers to match HubSpot’s property names before you upload saves that step.
How big can a HubSpot import file be?
It depends on your subscription. The same article lists:
| Limit | HubSpot free tools | Smart CRM, Starter, Professional or Enterprise |
|---|---|---|
| Maximum file size | 20 MB | 512 MB |
| Imports per day | 50 | 500 |
| Rows per day | 500,000 | 10,000,000 |
| Rows per file | Not stated separately | 1,048,576 |
| Simultaneous imports | 3, up to 2 over 10,000 rows | 3, up to 2 over 10,000 rows |
HubSpot notes these limits apply to “a rolling 24-hour period and do not reset at a specific time of day,” and that on free tools, files with more than 500,000 rows “will take multiple days to complete.” If you are near a limit, removing duplicate and empty rows first is the easiest way to get under it.
How should I format dates, phone numbers and checkboxes?
HubSpot validates values against each property’s field type. The main rules from its article:
- Dates. Months can be a number, three letters or a full name, and years two or four digits, with slash, hyphen or period separators. HubSpot accepts day month year, month day year or year month day order. Timestamps can be added as hh:mm, or as a UNIX timestamp in milliseconds in CSV files.
- Phone numbers. For the Phone number and Mobile phone number properties, format as ”+[country code][number]” to have HubSpot format it by country, with “ext” for extensions. Its example is “+11234567890 ext123.”
- Dropdowns and other enumeration properties. Values must match the label or the internal value of the property’s options. For HubSpot’s default ones, such as Lifecycle stage, they must match the internal value or the English label.
- Multiple checkboxes. Separate values with a semicolon and no spaces, such as “value 1;value 2.” Start with a semicolon to add values instead of overwriting.
- Single checkbox. Use True or Yes for checked, and False or No for unchecked.
- Percentages. Use “25%” or “.25.”
Two of these trip up exports from other systems all the time. Mixed date styles in one column, such as “03/04/2026” from one source and “2026-04-03” from another, are ambiguous between day-first and month-first. And dropdown values that differ only by spelling or case, such as “Customer,” “customer ” and “Cust.”, will not match the option list until they are made identical.
What columns does HubSpot need to create records?
HubSpot lists required properties by object. For creating new records:
- Contacts: Email. First name and Last name are recommended for basic identifying information.
- Companies: at least one of Name or Company domain name. HubSpot notes that domain values only keep up to the top-level domain, so anything after it is removed.
- Deals: Deal name, Pipeline and Deal stage, and the pipeline and stage must match ones that exist in your account.
- Tickets: Ticket name, Pipeline and Ticket status.
If you are updating existing records instead, you need a unique identifier such as Record ID, Email or Company domain name.
What happens to blank cells and duplicates?
HubSpot says its import tool “ignores blank cells,” so leave a cell blank when a record has no value. The flip side matters for updates: blank cells “will not clear the existing property value.” If you want to wipe a field in bulk, you have to do it inside HubSpot, not with an empty column.
For contacts with more than one email address, HubSpot wants the extra addresses in an “Additional email addresses” column, separated by semicolons. It also says you cannot create a new contact whose Email is already an additional email on another record. So duplicate or overlapping addresses in your file are worth catching before you import.
How do I clean a CSV before importing it into HubSpot?
A practical pre-import checklist:
- Check the encoding. If accented names show odd pairs of symbols or question marks where the accents should be, the file was read or saved with the wrong encoding. Fix it before upload and save as UTF-8. Our guide to CSV UTF-8 vs CSV Comma delimited explains why.
- Rename headers to match HubSpot property names.
- Trim and normalize emails: remove spaces, make them lowercase and drop obviously invalid ones.
- Standardize dates in each column to one unambiguous format.
- Standardize dropdown values so they match your option labels exactly.
- Format phone numbers with a plus sign and country code.
- Remove duplicate rows, including near-duplicates such as the same person with different capitalization.
- Protect IDs and postal codes. If Excel touched the file, leading zeros may already be gone. See how to stop Excel removing leading zeros.
Fix encoding, normalize emails and dates, and remove duplicates in a few clicks, offline.
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How does CSVPrune help with HubSpot imports?
CSVPrune is a private CSV cleaner and viewer for Windows that does this checklist without uploading your customer list anywhere. According to its Microsoft Store listing, you can:
- Fix encoding and delimiter problems, including UTF-8, UTF-16 and Latin-1, and comma, semicolon, tab or pipe separators.
- Keep leading zeros and long IDs intact, never silently changed.
- Trim whitespace, normalize emails and standardize text, numbers, dates and booleans.
- Remove exact duplicates, or catch near-duplicates with fuzzy matching.
- Find and replace with plain text or regex, scoped to one column, which is handy for fixing dropdown spellings.
- Profile columns to spot invalid values, with a data-quality score.
- Save your cleaning steps as a recipe and replay them on next week’s export with one click.
- Export to CSV, JSON or XLSX, with no cloud, no telemetry and no network calls.
Recipes are the part that pays off for regular imports. If you import a form or event export into HubSpot every week, the same fixes apply every time.
CSVPrune keeps data in memory, so very large files depend on your PC’s RAM. Check the cleaned file’s encoding and a sample of rows before your first real import, and run a small test import in HubSpot if you are updating existing records.
Frequently asked questions
Does HubSpot accept Excel files or only CSV?
Both. HubSpot accepts .csv, .xlsx and .xls, as long as the file has only one sheet.
Why are accented names broken after a HubSpot import?
Usually the file was not UTF-8. HubSpot requires UTF-8 when a file includes non-English characters, so re-save or convert it before importing.
What is the maximum number of rows in a HubSpot import?
Paid subscriptions can import up to 1,048,576 rows per file and 10,000,000 rows per day. Free tools allow files up to 20 MB and 500,000 rows per day.
Will an empty cell erase a value in HubSpot?
No. HubSpot ignores blank cells, so existing values stay. Clear them inside HubSpot instead.
Can I use the same cleanup for Mailchimp?
The steps are similar, but each platform has its own rules. See our guide to cleaning a CSV for Mailchimp import.
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Get CSVPrune from the Microsoft Store. It is a one-time purchase with no subscription, and the Store listing shows the current price.
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HubSpot is a trademark of HubSpot, Inc. Microsoft, Windows and Excel are trademarks of the Microsoft group of companies. Mailchimp is a trademark of its respective owner. CSVPrune is not affiliated with or endorsed by HubSpot, Microsoft or Mailchimp.
Last updated 23 October 2026. Published by Automata Labs, a software company in Canada.