How to Import a CSV Overlay

Annie Johnson

November 11, 2026 21:47

This article covers:

What is a CSV overlay?
Formatting requirements for a CSV overlay
What cannot be overlaid
Importing a CSV overlay with the Load File Mapper

What is a CSV overlay?

An overlay is an index file, formatted as a CSV, that updates the metadata or coding of documents already imported into your Discovery or Litigation database. Overlays are applied through the Overlay workflow.

The Load File Mapper lets you match fields in your CSV overlay file to fields in your Nextpoint database, and Nextpoint validates the load file and fields along the way to help your overlay run successfully.

Key features:

Run CSV overlays with the CSV Overlay import type.
Use a document mapping key to tell Nextpoint which documents in your database to update.
Map fields with exact match recommendations, search for other existing fields, or create new fields during mapping.
Revert an overlay if needed using the Backup Overlay File.

This functionality is available to Advanced users only.

Completed overlay in the Overlays tab

Formatting requirements for a CSV overlay

The first row of your overlay file must contain column headers (field names). Each row after that represents one document.

Example CSV overlay file with a header row and one row per document

Overlay column headers fall into three categories, each described in the tabs below:

Document keys: locate the specific document each row applies to.
Nextpoint system fields: available in every database and not configurable.
Nextpoint custom fields: fields created and configured by users.

Format column headers as lowercase, underscore-separated values (for example, document_date). Nextpoint will attempt to convert headers like "Document Date" to document_date, but formatting them before you upload the file to the File Room gives the most reliable results.

Save your overlay file as a CSV with UTF-8 encoding.

What Cannot Be Overlaid

Bates, Custodians, Native_File, and Text_File cannot be overlaid. Contact Nextpoint Support for assistance with these fields.

Responsive Issues, Relevancy, and Privilege cannot be written by an overlay. They are protected, application-managed fields (see Nextpoint Default and Protected Fields). Issue abbreviation columns work only in load files used at import, not in overlays. To apply review calls made outside Nextpoint to documents that are already imported:

Overlay the review calls into a custom field (see the Custom Fields tab below), keyed on npid or bates_start.
Search on that custom field to find the documents.
Bulk code the search results as Responsive.

Each row in the CSV must contain at least one document key value. The document key tells Nextpoint which document in your database to update with that row's data. Available keys:

CSV Header	Description
`npid`	The Nextpoint ID of a document. Export it in bulk using the Nextpoint ID export field. For an individual document, it is listed as DocID under System Data. Tip: This is the most accurate and preferred key. It is always unique and runs the fastest.
`bates_start`	The Bates number on the first page of a document in Nextpoint. Export it in bulk using the Bates Range Start export field.

After the document key in the first column, add a column for each field you want to overlay. Each row then contains the data to overlay into those fields for that document.

The table below lists the default system fields you can overlay. For fields that cannot be overlaid, see What Cannot Be Overlaid above. The only other fields an overlay can write to are custom fields, described in the Custom Fields tab.

CSV Header	Description
`app_name`	Appears as "App Name" under coding fields.
`author`	Does not appear under coding fields, but is available for mapping. Often a merged field of `document_author` and `email_author`.
`bcc`	Appears as "BCC" under coding fields.
`cc`	Appears as "CC" under coding fields.
`created_date_time`	Date field. Use American date formatting (MM/DD/YYYY).
`document_author`	Appears as "Document Author" under coding fields.
`document_date`	Appears as "Document Date" under coding fields. Date field. Use American date formatting (MM/DD/YYYY).
`document_last_author`	Appears as "Document Last Author" under coding fields.
`document_subject`	Appears as "Document Subject" under coding fields.
`document_title`	Appears as "Document Title" under coding fields.
`document_type`	Appears as "Document Type" under coding fields.
`email_author`	Appears as "Email Author" under coding fields.
`email_received`	Date field. Use American date formatting (MM/DD/YYYY).
`email_sent`	Date field. Use American date formatting (MM/DD/YYYY).
`email_subject`	Appears as "Email Subject" under coding fields.
`encrypted`	Appears as "Encrypted" under coding fields.
`file_name`	Appears as "File Name" under coding fields.
`file_path`	Appears as "File Path" under coding fields.
`last_print_date`	Date field. Use American date formatting (MM/DD/YYYY).
`mailbox_file`	Appears as "Mailbox File" under coding fields.
`mailbox_path`	Appears as "Mailbox Path" under coding fields.
`modified_date_time`	Date field. Use American date formatting (MM/DD/YYYY).
`np_folder_prefix`	Does not appear under coding fields, but is available for mapping. Adds documents to a folder through an overlay. Values must be an existing folder abbreviation or prefix. Use with `np_folder_position`. This article explains how.
`np_folder_position`	Does not appear under coding fields, but is available for mapping. Sets each document's position in the folder (for example, a value of 6 places the document sixth). Use with `np_folder_prefix`. This article explains how.
`recipients`	Appears as "Recipients" under coding fields.
`root_folder`	Appears as "Root Folder" under coding fields.
`shortcut`	Appears as "Shortcut" under coding fields.
`title`	Does not appear under coding fields, but is available for mapping. Often a merged field of `document_title` and `email_subject`.

In addition to the system fields in the previous tab, you can overlay data into any custom field you create in your database.

Use lowercase column headers, with spaces in the custom field name replaced by underscores. For example, a field named "City Name" uses the header city_name.

How you format each cell depends on the field type:

Field Type	Cell Format
Freeform & Paragraph	Any value can be provided.
Date	Nextpoint will attempt to convert the value to YYYY-MM-DD HH:MM:SS (24-hour) format, which custom date fields require because it is sortable. If a value cannot be converted, the original value is overlaid as provided. Note: American date formatting is always used, so provide dates in the format above.
List & Locked List	The exact list option to apply. If the option does not exist, it will be created.
Picklist	A semicolon-separated list of the picklist options to check. For example, `Option 1;Option 2; Option 3` is applied as: Option 1 Option 2 Option 3 Spaces before and after each value are trimmed. Note: All existing picklist selections on the document are removed and replaced with the values in this field. The picklist options themselves are not changed.
Single Checkbox	Any value checks the checkbox. An empty cell leaves it unchecked.

Importing a CSV overlay with the Load File Mapper

The documents you want to overlay must already be imported into your Nextpoint database before you start.

1 | Upload the CSV overlay file to the File Room

Go to the File Room. In Discovery databases, go to DATA File Room. In Litigation databases, go to MORE Data File Room.
Upload your CSV overlay file(s) using one of the following options.

Upload a folder by drag and drop: Drag the folder from your desktop, thumb drive, or other location into the File Room. All contents and subfolders are kept.

Upload loose files by drag and drop: In the File Room, click the green Create Folder button, name the folder, and click OK. Open the new folder and drag your overlay file into it. Keeping overlay files in their own folders makes it easier to track your overlays over time.

Request the file from a third party: If you are receiving the overlay file from a third party, such as opposing counsel, you can securely request it through your File Room. The recipient gets a secure link to upload the file, and you can access it as soon as it is uploaded. Read more on requesting files from third parties.

Best Practices for Uploading

Overlay files must be in CSV format. Excel and .dat files are not supported.
Store overlay files with the data set you are overlaying, or in a dedicated Overlay Files folder in the File Room, so they are easy to find later.

2 | Start the overlay

Once your overlay file is in the File Room, go to the Overlays tab under DATA and click the blue Start an Overlay button.

Start an Overlay button in the Overlays tab

3 | Confirm overlay settings

On the Overlay Settings screen, set the following:

Overlay File Selection: Click the folder icon to open the File Room and select your overlay file.
Overlay Name: Name the overlay so it is easy to identify after it is complete.
Backup restored data: On by default. Saves the existing field values to a separate CSV file before any data is overlaid, so you can revert the overlay if needed.

4 | Review and set overlay mappings

Load File Mapper at a glance

In the Load File Mapper, you map each field in your overlay file to a field in your Nextpoint database. Any field that is not mapped will not be overlaid, because Nextpoint will not know where to send that data.

The mapper has four columns:

Load File Mapper with columns A through D labeled

A | Field from your load file: The fields in the header row of your overlay file.
B | Destination field: The Nextpoint database field each overlay field maps to. Nextpoint auto-maps exact matches. You can change the mapping, create a new destination field, or skip the field.
C | Load file preview: A three-row preview of each field's data, so you can confirm the values match the field.
D | Field status: Shows whether each field is mapped or needs action before you can continue.

Document mapping

The first row of the Destination field column is the document mapping key, which tells Nextpoint how to find each document to update. See the Document Keys tab in Formatting requirements for a CSV overlay for the available keys.

Click the gear icon to confirm which load file field Nextpoint should use to locate the documents.

Selecting the document mapping key with the gear icon

Note: In the example above, the duplicate ProdBeg (bates_start) field is skipped. Bates cannot be overlaid, so it only needs to be used as the document mapping key.

Auto-mapping

For each field in column A, Nextpoint first looks for an exact match with an existing destination field. Exact matches are mapped automatically. In the example below, BegAttach and BCC are exact matches, so they are auto-mapped.

Auto-mapped fields in the Load File Mapper

User mapping

If a field has no exact match, you can map it to an existing field or a new one. In the example below, Tags is not auto-mapped because there is no exact match (and tags cannot be mapped), so you choose where that data goes.

Each Destination field has a dropdown listing every field available for mapping in the database.

Destination field dropdown in the Load File Mapper

Text styles in the dropdown show the field type:

Normal text: Default fields that exist in every Nextpoint database. Map to these when possible for easier searching later.
Grayed out: Fields already used in another mapping. Change or remove the other mapping to use one of these.
Bold text: Custom (user-created) fields.

Create a new field for mapping

If the field you need is not in the dropdown, click the create field icon icon to the right of the Destination field to create it.

Create new field icon in the Load File Mapper

Confirm the suggested name or enter your own, then click Create. The field is added to your database immediately and can be used for mapping.

Naming a new field and clicking Create

Skip fields

Skipping a field means its data will not be overlaid, so Nextpoint requires you to skip fields explicitly by selecting Skip Field in the Destination field dropdown. You can also skip all unmapped fields at once before moving to processing.

Skip Field and skip all unmapped fields options

5 | Run the overlay

Once all fields are mapped or skipped, click the blue Overlay button at the bottom right to start processing. Nextpoint makes a copy of your overlay file with your mapping selections and handles any needed conversions during processing.

Overlay button in the Load File Mapper

Warning: Overlays overwrite existing data

Every field included in the overlay is fully overwritten by the values in the CSV. If a cell is empty, the existing data in that field is removed in Nextpoint.

Before you run the overlay, confirm Backup restored data is enabled in your overlay settings, so you can revert the changes if needed.

6 | Review overlay results

After the overlay is complete, review the results to confirm the data mapped as expected. Go to DATA Overlays and click the overlay name in the batch list.

The following files and reports are generated during processing:

Processed overlay file: Saved to the File Room folder you selected, reflecting your Load File Mapper selections.
Field Mapping Report: The fields used for mapping, saved on the overlay details page.
Processing Results Report: The document mapping key used, the Nextpoint DocIDs it matched, and the coding or metadata applied.
Backup Overlay Load File: A CSV of the documents in the overlay batch and their coding or metadata before the overlay. Use it to revert the overlay if needed.

7 | Family link

Note: This step only applies if you overlaid email family relationships using the bates_start document mapping key and the BegAttach field.

Family linking visually links produced emails and their attachments using two fields: Unique ID and Family ID. Run it after processing is complete.

Go to DATA Overlays and click the overlay name to open the Batch Details. At the bottom right of the Batch Summary page, click . A panel opens listing batches (with batch number, importing user, upload date, and document count) and a Linking Options dropdown.

Select the overlay batch(es) to family link.
In the Linking Options dropdown, select the fields Nextpoint should use to link parent emails to their attachments.
Click Family Link Documents.
Click Run Family Linking to confirm.

Overlay status

When processing finishes, the overlay shows one of three statuses: green Complete, yellow Complete With Errors, or red Error. For help resolving errors, see Common Overlay Errors and Solutions.