Ontraport allows you to create custom fields to use in your account, but the amount of fields that you are allowed depends on the field’s type and its data usage.

Maximum number of fields


Custom fields have a data allowance of up to 39,611 bytes per account. Each field uses a different amount of bytes, so there is no set number of total fields per account. Instead, using the listed byte amounts below you can decide how many of each you will use to stay under the 39,611 data limit.

Field Type Bytes Required
Checkbox 1
Date 20
List Selection 20
Long Text 8
Numeric 20
Price 64
Phone 768
State 768
Dropdown 20
Color 20
Text 768
Email 768
SMS 768
Address 768


To Mitigate Data Limitations

In cases where the field editor will not allow new fields to be created, you can make space for more custom fields by converting your text fields to long text. Text fields take up 768 bytes per field, while long text fields take only 8. Since long text fields can hold more characters than standard text fields, you won’t lose data by converting. Before you convert your fields, there are two things you should keep in mind:

  • Long text fields are stored in another database, which means if you have a large number of long text fields, it may take longer to fetch the data.
  • Long text field cannot be used as a column heading in a list view.

To convert your text fields to long text fields:

  • Hover over Contacts and click Settings > Field Editor.
  • Select the text field you would like to convert.
  • Click the field type dropdown, then select Long Text. You will not be able to convert a long text field back to a text field.