# Import file settings, data actions and field mapping

*Marketing Cloud Engagement Specialist Study Guide · Subscriber and Data Management · Last updated October 29, 2026 · https://www.certifyforce.com/study-guide/marketing-cloud-engagement-specialist/subscriber-and-data-management/import-file-settings-data-actions-and-field-mapping*

The settings that make an import succeed: file requirements, delimiters and their file extensions, case-sensitive FTP names, date format and encoding, the four data actions, Map by Header Row, Ordinal (zero-based for lists) or Manually, and why primary key defaults and nulls reject rows.

- Certification: Salesforce Marketing Cloud Engagement Specialist
- Exam section: Subscriber and Data Management
- Study guide: https://www.certifyforce.com/study-guide/marketing-cloud-engagement-specialist

**Official exam objective:**

> Given a customer's business requirements, determine how to import data into Marketing Cloud.

## What the exam expects

- Check a file against the Import Wizard's requirements: header row, at least one data row, a delimited format, size and name length.
- Set the delimiter, file name, date format and encoding so the file is found and read correctly.
- Choose Add and Update, Add Only, Update Only or Overwrite from what must happen to new and existing rows.
- Choose Map by Header Row, Map by Ordinal or Map Manually, and number ordinal columns correctly for lists and data extensions.
- Key terms: **data action** (import type: how rows are written to the destination); **text qualifier** (double quotes that wrap a value containing the delimiter); **Map by Ordinal** (columns matched by position); **File Naming Pattern** (the activity's file name, which can be dynamic by date); **Nullable** (whether a field may be empty on import).

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Wizard file | Header row plus at least one data row; delimited; 20 MB max | [Import into a Data Extension](https://help.salesforce.com/s/articleView?id=sf.mc_es_import_into_de.htm&language=en_US&type=5) |
| My Computer file name | 99 characters or less | [Import into a Data Extension](https://help.salesforce.com/s/articleView?id=sf.mc_es_import_into_de.htm&language=en_US&type=5) |
| FTP file name | Case-sensitive | [Import into a Data Extension](https://help.salesforce.com/s/articleView?id=sf.mc_es_import_into_de.htm&language=en_US&type=5) |
| Comma / Tab / Other | .csv / .txt / one-character delimiter | [Import into a Data Extension](https://help.salesforce.com/s/articleView?id=sf.mc_es_import_into_de.htm&language=en_US&type=5) |
| File Encoding | Defaults to UTF-8 when empty | [Import into a Data Extension](https://help.salesforce.com/s/articleView?id=sf.mc_es_import_into_de.htm&language=en_US&type=5) |
| Add only | New keys created; existing keys ignored | [Import into a Data Extension](https://help.salesforce.com/s/articleView?id=sf.mc_es_import_into_de.htm&language=en_US&type=5) |
| Primary key default | Not applied during imports | [Import into a Data Extension](https://help.salesforce.com/s/articleView?id=sf.mc_es_import_into_de.htm&language=en_US&type=5) |
| Primary key column | Required unless Overwrite | [Import or Copy a Large Dataset](https://help.salesforce.com/s/articleView?id=mc_as_update_a_list_or_data_extension_using_an_external_file.htm&language=en_US&type=5) |
| Map by Ordinal | Lists start at 0; data extensions at 1 | [Import or Copy a Large Dataset](https://help.salesforce.com/s/articleView?id=mc_as_update_a_list_or_data_extension_using_an_external_file.htm&language=en_US&type=5) |
| Dated daily files | Dynamic File Naming Pattern; Blank File Behavior for empty files | [Import or Copy a Large Dataset](https://help.salesforce.com/s/articleView?id=mc_as_update_a_list_or_data_extension_using_an_external_file.htm&language=en_US&type=5) |

## Check yourself

- Why must the file name end in .zip when Compressed is selected?
- Which ending must an import file name have when Encrypted is selected without Compressed?
- Why would a wizard reject a header-only file?
- What does the Import Wizard default to for the import type and for bad rows?

## Sources

- [Import into a Data Extension](https://help.salesforce.com/s/articleView?id=sf.mc_es_import_into_de.htm&language=en_US&type=5)
- [Import or Copy a Large Dataset Using an External File as the Source](https://help.salesforce.com/s/articleView?id=mc_as_update_a_list_or_data_extension_using_an_external_file.htm&language=en_US&type=5)
- [Improve Email Campaigns with Data Extension Imports](https://trailhead.salesforce.com/content/learn/modules/email-creation-and-sending/import-subscriber-data)
- [Data Transfer and Import Activities](https://trailhead.salesforce.com/content/learn/modules/marketing-cloud-data-management/move-your-data)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 9 linked practice questions, and unlimited timed mock exams are included with the Marketing Cloud Engagement Specialist pack (USD $19): https://www.certifyforce.com/practice-exams