topic “Don’t Overwrite” Option During Contact Import – Does It Append or Preserve Only? in Tips, Tricks & Best Practices

“Don’t Overwrite” Option During Contact Import – Does It Append or Preserve Only?

md2727 — Fri, 21 Mar 2025 20:59:16 GMT

Hi everyone,

I’m trying to better understand how the “Don’t overwrite existing values” option works when importing contacts into HubSpot.

During the import process, the "don't overwrite" label says: "When a record in your import matches a record that already exists in HubSpot, the existing value is overwritten with the new value by default. To keep existing data as-is, select Don’t overwrite."

From what I understand, this option keeps existing data in place and only fills in blank fields — but I’m not sure how it behaves with fields that allow multiple values, like multi checkboxes. My questions: Does this option append new values to existing ones in multi-select fields, or does it completely skip the field if there’s already data? What’s the best way to update multi-select properties via import without removing what’s already there?

Thanks,

Re: “Don’t Overwrite” Option During Contact Import – Does It Append or Preserve Only?

karstenkoehler — Fri, 21 Mar 2025 21:19:35 GMT

Hi @md2727,

If you choose the 'Don't overwrite' option, existing multiple checkboxes property values would not be changed, neither overwritten nor appended.

If you want to append, you can find instructions here: https://knowledge.hubspot.com/import-and-export/set-up-your-import-file#format-values-based-on-property-field-type

In short: start with a semicolon to append. Do not select 'Don't overwrite'.

Best regards!

Re: “Don’t Overwrite” Option During Contact Import – Does It Append or Preserve Only?

TheAdminArena — Fri, 21 Mar 2025 21:04:12 GMT

I'm pretty sure if you check the "don't overwrite" box it will essentially ignore the property. Specific to your question: it won't append the data, it will simply ignore that property altogether.

The best way to update multi select via import is to:

Export the records, update the values in excel, reimport with all of the values that you want checked
- Use the above approach and overwrite what's in there

Re: “Don’t Overwrite” Option During Contact Import – Does It Append or Preserve Only?

md2727 — Fri, 21 Mar 2025 21:29:53 GMT

Thanks, Karsten! But it's just a manual import, isn't it? So I’d need to manually update the CSV file with multiple options and then do the import? If that’s the case, it’s really not useful. I have hundreds of thousands of contacts in my HS database, and it's practically impossible to manage this manually. Is there any other way to append new values to the field without removing the existing ones during the import?

Re: “Don’t Overwrite” Option During Contact Import – Does It Append or Preserve Only?

karstenkoehler — Fri, 21 Mar 2025 21:34:19 GMT

@md2727 starting with a semicolon will append, not replace. Have you reviewed the linked article?

"To import multiple values, add a semicolon between each value without spaces (value 1;value 2). These property options must be created prior to the import.

To add or append values, add a semicolon before the first value (;value 3;value 4). This will append the value instead of overwriting the existing property value."