# Create a custom field

**Category:** [Time Tracking](https://help.totalctrl.app/hc/totalctrl/totalctrl-help-center/en-US/categories/time-tracking)
**Updated:** 2026-08-06

## Add one

- Go to **Time Tracking › Custom Fields › Fields** and choose **New field**.

- Give it a **label** — what people logging time will read, e.g. *Work type*.

- Set the **API key** — the lowercase, underscored name the API and the mobile app use, e.g. `work_type`.

- Pick a **type**.

- For a picklist, list the **options**, one per line.

- Optionally add **help text**, shown under the field when logging time.

## Field types

TypeUse for

TextFree text — a reference, a note
NumberQuantities, counts
DateA date other than the logged date
Boolean (Yes/No)A simple flag
Select (picklist)One choice from a fixed list — best for reporting
Multi-selectSeveral choices from a fixed list
URLA link to a ticket or document

Prefer a **picklist** over free text for anything you plan to report on. Free text gives you “Build”, “build” and “Building” as three separate answers.

## The API key cannot be changed later

Every value already collected points at that key. Renaming it would leave those values attached to a name nothing looks for, so the field is created with its key and keeps it. The **label** can be changed freely — change that when the wording needs to improve.

## “Required by default”

This is a starting point for new templates, not a workspace rule. Whether a field is actually required is set **per template**, because the same field can be mandatory for one client and optional for another.

## Deleting a field

Deleting a field also deletes every value collected for it, on every entry, and removes it from every template. Export a report first if you need the history.

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## Related Articles

- [Track your time](https://help.totalctrl.app/hc/totalctrl/totalctrl-help-center/en-US/articles/track-your-time)
- [Templates, and giving one to a project](https://help.totalctrl.app/hc/totalctrl/totalctrl-help-center/en-US/articles/timetracking-field-templates)
- [Filter, sort and group reports by a custom field](https://help.totalctrl.app/hc/totalctrl/totalctrl-help-center/en-US/articles/timetracking-reporting-custom-fields-1)
- [Custom fields in the API and AI tools](https://help.totalctrl.app/hc/totalctrl/totalctrl-help-center/en-US/articles/timetracking-custom-fields-api-1)
- [Configure project billing and budgets](https://help.totalctrl.app/hc/totalctrl/totalctrl-help-center/en-US/articles/project-billing-and-budgets)

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