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8 recommendations to fix your CSV errors
8 recommendations to fix your CSV errors
A useful know-how to fix issues when uploading CSVs [Reading time: 3 minutes]
Eva Kriegel avatar
Written by Eva Kriegel
Updated over a week ago

This article will help you better understand the challenge of how to upload your contacts properly and quickly.

We're guessing you're here because you've faced uploading issues before, or maybe you'd like to prepare for every eventuality. Or you are just interested.

It's easier than you think to fix CSV issues... and the solution is usually hidden behind the curtain.

1. Did you remove any empty value from your Excel sheet?

The most common occurrence is when you have an Excel file full of

  • unnecessary data

  • line spacings

  • empty value

To correct the .CSV delete all the unnecessary columns and rows, not only the content from the fields.
Unless all the deleted content remains as empty data fields. These might be mapped as “Object” during import and will be displayed like this:




Jimmy;"Hendrix";"";"Guitar God","","2019-05-16";;;;;;;;


Johnny English;University of Budapest;1234;;



Other content, other content

Other content, other content

Johnny Bravo;University of Art;5678;;

Correct form:


Check the CSV file and if you see separate characters without any data between them, you need to make some corrections.

Delete the entire columns, not only the inserted data.

2. Did you choose the correct type of Custom Field?

The most common occurrence is when you have text or special characters in a number type custom field.

For example, you have a column in your sheet for phone numbers and you map it as a number type custom field.
If some contacts have a “+” or a “/” in their phone number, this data will be considered TEXT.

In this case the system will skip this data. Contacts who have a “+” or a “/”  or no data in their phone number will not be imported.


Use the TEXT field by phone numbers, postal codes, etc.

Choosing NUMBER type is a good option if you plan to segment based on this number. 

Fe.: employee number

3. Is your data in a date-type custom field correct?

A specific date can be defined in a myriad of ways, but we also need to consider what software and email clients accept.

Use one of these following formats to be sure that your date-typed custom fields will be uploaded to your contacts' profile and later on email clients will display it smoothly.

yyyy-MM-dd [HH[:mm[:ss]]]
yy-MM-dd [HH[:mm[:ss]]]
ISO_DATE_TIME (e.g. '2011-12-03T10:15:30+01:00[Europe/Paris]')
ISO_INSTANT (e.g. '2011-12-03T10:15:30Z')
yyyy.MM.dd [HH[:mm[:ss]]]

4. How is your CSV encoded? 

You can use UTF-8 or ANSI encoding with the appropriate profile settings.

If your CSV file is UTF-8 encoded (your character separator is , ), please make sure your profile setting is UTF-8. 

If you use ANSI encoding (your character separator is ; ) your profile setting should be ISO-8859-2.


If your file isn't properly necoded, then none of your contacts will be added to your list. This can happen if you are saving an XLS file as a CSV file.
To ensure your file is UTF-8 encoded use Google Sheets to create the file and then export that as a CSV
Open your CSV in Libre Office to see what is the type of encoding.

5. How many contacts do you have?

Thousands of contacts with hundreds of custom fields need a little time to be uploaded properly.

Mizy is working hard in the background, just needs some patience.


Break the file down into multiple, segmented list and remove all custom fields you don't need.

6. All of your contacts have an email address, right?

 Valid email addresses are required for every contact. If you do not list an email address, or if you have included an email address that is not properly formatted, the contact will get skipped.


Make sure that each contact has an email address in the same column and that they are formatted properly.

7. Are your contacts listed only once in the sheet? 

Seems to have fewer contacts in Automizy, then in your CSV? If any of your contacts are duplicated, we will upload them once. The second one will be skipped.


Make sure that your contact(s) is not duplicated.

8. How do you use special characters?

 Special characters include but are not limited to apostrophes (') and backslashes (\). 


When you have any characters in your file, make sure to use double-quotes in your file.
For example: O'Conner -> “O'Conner”

7. Has your CSV file more contacts than your plan allows? 

To increase your customer base, it is necessary to stay in constant contact with potential and existing customers. Then you will need to upgrade your account on the Billing & Upgrade page.

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