> ## Documentation Index
> Fetch the complete documentation index at: https://docs2.zenskar.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How-to: Ingest usage events via CSV upload

You can upload usage data in CSV format directly from the Zenskar dashboard. This method is designed for bulk ingestion and one-time imports without writing code.

## When to use this

* Backfilling historical or missing usage data
* Importing aggregated or pre-processed usage summaries
* Migrating data from another billing or analytics system
* Onboarding new customers or syncing legacy records

## CSV file requirements

Your CSV file must meet the following criteria:

* Include a header row with column names
* Contain at least these required columns:
  * `customer_id` (string)
  * `timestamp` (ISO 8601 date/time)
  * At least one usage column, such as `api_call_count` or `storage_gb`
* Support additional columns based on your schema (e.g., `region`, `feature_id`)
* Have a consistent timestamp format that matches your usage event schema

## How to upload a CSV file

1. In Zenskar, navigate to **Usage > Usage data**.
2. Click the dropdown next to **Upload CSV**, then select **Upload usage file**.
3. In the modal:
   * Choose your CSV file.
   * Map columns to the corresponding schema fields (e.g., `customer_id`, `timestamp`, `usage value`).
4. Click **Upload**.
5. The dashboard will validate your file. If errors are found, they’ll be highlighted for review.
6. Once validation passes, click **Confirm upload**. Zenskar will process the file and insert the data into the ingestion table.

## What happens next

* Zenskar processes the data and stores it in a secure ingestion table.
* Aggregates in CSV format can be used directly as **billable metrics**.
* If raw events are uploaded, you'll need to define **billable metrics** through the metric builder.
* All uploaded data is available under **Metering > Ingestion table** for review.

## Pros and cons

| Pros                                      | Cons                                          |
| ----------------------------------------- | --------------------------------------------- |
| Bulk ingestion without engineering effort | Manual process—may not suit recurring uploads |
| Backfill any period of data quickly       | Needs careful handling of duplicates          |
| Supports aggregates for immediate billing | Validation errors may require file updates    |

## Next steps

* Automate ingestion using [connectors or APIs](../data-ingestion-via-apis)
* Create billable metrics from ingested data in the [Billable Metrics](/docs/core-concepts/billable-metrics) guide
* Explore [connecting data warehouses or data stores](https://docs.zenskar.com/docs/data-ingestion-via-data-source-connectors) for continuous data sync

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