Custom fields overview: what they are and where they live
The big picture on custom fields — what they store, the field types available, how folders keep them organized, and where they show up across the platform.
Every contact record ships with a fixed set of fields — First Name, Last Name, Email, Phone, Address. That's plenty for a rolodex, but it's rarely enough to actually run a business on. A property management company needs to track move-in dates. A med spa needs to know which treatments a client is interested in. A roofing contractor needs roof age and insurance carrier. Custom fields are how you add exactly those questions to your records, without waiting on anyone to build them for you.
What a custom field is
A custom field is a piece of data you define yourself, attached to a record type, that behaves just like a built-in field once it exists. It shows up on the record, can be asked for on a form, can be referenced in a workflow, and can be inserted into an email or text as a merge tag. The only difference from a standard field is that you created it — which means you control the name, the type, and what happens to it.
The Custom Fields settings page listing existing fields grouped into folders
Note: Custom fields aren't limited to contacts. Depending on your account, you can also add custom fields to opportunities and other record types, each with their own field list.
Field types available
When you create a field, you pick a type that controls how the data is entered and validated:
| Type | Best for |
|---|---|
| Single line text | Short free-text answers — a job title, a referral name |
| Multi-line text | Longer notes — special instructions, a project description |
| Number | Anything you'll do math on or sort numerically — budget, square footage |
| Date picker | A specific date — move-in date, renewal date, birthday |
| Dropdown (single) | One choice from a fixed list — lead source, plan tier |
| Dropdown (multiple) | More than one choice from a fixed list — services interested in |
| Radio select | A single choice shown as buttons instead of a dropdown |
| Checkbox | A yes/no or multi-select group shown as checkboxes |
| Phone | A phone number, formatted and validated as one |
| Yes/No (toggle) | A simple boolean flag |
| File upload | Letting a contact attach a document or image through a form |
| Signature | Capturing a signature through a form |
Pick the narrowest type that fits. A dropdown with a fixed list of lead sources keeps your data clean for reporting; a free-text field for the same purpose eventually collects five spellings of "Facebook."
Tip: If you're building a field mainly so you can filter and segment on it later, use a dropdown or checkbox group instead of free text. Smart lists filter cleanly on fixed options; they filter poorly on inconsistent typed answers.
Folders: keeping a long field list usable
Once an account has been running for a while, it's common to have thirty, fifty, or more custom fields. Folders group related fields into labeled sections so the record view (and the field picker when you're building a form) stays organized instead of becoming one long unsorted list. Typical folders might be "Buyer Information," "Property Details," "Sales Qualification," or "Appointment Preferences."
Folders are purely organizational — they don't change what a field does or where its data lives. You can create a folder, move existing fields into it, and reorder folders from the same settings screen where you manage the fields themselves. This is covered step by step in Create and manage custom fields.
Contact fields vs. other object fields
The most important decision when creating a field is which object it belongs to:
- Contact fields attach to a person. They appear on every contact's record, can be asked for on any form or survey, and are available in any automation triggered by that contact — regardless of which deal, if any, the contact is tied to.
- Opportunity fields (and fields on other custom objects, where enabled on your account) attach to a specific deal or record instead of the person. Use these for data that's true of this particular deal but might differ the next time the same person comes through your pipeline — budget for this specific project, expected close date, unit interested in.
This choice is permanent. Once a field is created as a contact field or an opportunity field, it can't be switched to the other later. If you're not sure which one you need, ask: "Is this true about the person, or true about this specific deal?" If the answer changes depending on which opportunity you're looking at, it's an opportunity field.
Where custom fields show up
Once created, a custom field is available across the platform, not just on the form where you first added it:
- On the contact record (or opportunity record), as an editable field in the layout.
- In forms and surveys, as a question you can add to any form on the account.
- In smart lists, as a column and a filter condition.
- In workflows, both as a condition to branch on and as an action to update.
- In emails, SMS, and templates, as a merge tag that personalizes the message.
That reuse is the whole point: define "Preferred Appointment Type" once, and every form, workflow, and email on the account can read or write it the same way.
What "done" looks like
You should be able to look at any custom field in your account and answer three questions: what object it belongs to (contact or opportunity), what type it is, and which folder it lives in. If a field's purpose isn't obvious from its name, rename it — a clear name now saves a lot of guessing later, especially once dozens of people on your team are using the same field list.
Related articles
- Create and manage custom fields
- Use custom fields in forms, surveys, and the contact record
- Use custom fields in emails, SMS, and automations
Frequently asked questions
How many custom fields can I create?
There's no small, hardcoded limit for most account tiers — accounts commonly run dozens of fields across several folders. The practical limit is usability: an unfoclered field list of a hundred entries is hard for your team to work with, so lean on folders and clear naming as you grow.
Can two different forms use the same custom field?
Yes, and this is the recommended approach. Because the field lives on the contact (or opportunity) record rather than on any one form, any number of forms, surveys, or workflows can read from and write to the same field. Creating a near-duplicate field for a second form just splits your data across two places.
What happens to the data if I delete a custom field?
Deleting a field removes the stored answers for every record along with it, and this can't be undone. See Create and manage custom fields for what to check before deleting one.