How do Tally hidden fields track UTM parameters?
Tally hidden fields are invisible form fields that take their values from the form's URL parameters. Add hidden fields named utm_source, utm_medium and utm_campaign, link to the form with those parameters, and each submission records the campaign that sent it. Embeds need the host page's UTMs passed through.
- Add a hidden fields block to the form.
- Name one field per UTM parameter.
- Link or embed the form with the parameters.
- Send submissions to your sheet or CRM.
- Test with a tagged URL.
A tagged link opens the page with your Tally form, the hidden fields are filled, and the submission reaches your sheet or CRM with its source.
How to set up Tally hidden fields
- Open your form in Tally's editor.
- Insert a Hidden fields block. Type
/hiddenin the editor, or find it in the block menu. Tally's hidden fields help page has the current steps. - Add field names:
utm_source,utm_medium,utm_campaign,utm_term,utm_content. - Publish.
Map UTM parameters to the fields
With direct links, the parameters go in the query string, and Tally fills fields whose names match:
https://tally.so/r/FORMID?utm_source=linkedin&utm_medium=social&utm_campaign=webinar
| URL parameter | Hidden field | Stored as |
|---|---|---|
utm_source=linkedin | utm_source | |
utm_medium=social | utm_medium | social |
utm_campaign=webinar | utm_campaign | webinar |
Build the tagged URLs with the UTM builder so spelling stays consistent.
Tally embeds and UTMs
When the form is embedded on your site, the visitor's UTMs are on your page URL, not the form's. Tally's embed can forward the parent page's parameters; check Tally's embed docs for the current option. Either way it only sees the current page. If the visitor browsed from a landing page to a contact page, the values need to be saved on arrival and passed in, as covered in capturing UTM parameters in hidden fields.
Reporting on the source
Tally sends hidden field values with each submission to its integrations: Google Sheets, Notion, Airtable, webhooks and more. Group submissions by utm_source and utm_campaign in your sheet, or map them into CRM properties so the source sits on the lead.
That's the manual path. To skip it, pre-register for Trakt and each Tally submission arrives with its source attached.
Why Tally hidden fields break in practice (and how Trakt helps)
They're simple, which is why they get forgotten. A new form goes live without the block. The embed loses the parameters. Someone links to the form without tags.
How Trakt closes the gap
Trakt receives Tally submissions by webhook and stores each one with the source saved in the visitor's browser, so the campaign survives page changes. See the Tally integration. Trakt keeps the first touch, connects visits across devices, syncs source and revenue into your CRM, and sends new-lead alerts by email and Slack.
Manual vs. Trakt, by requirement
| Requirement | Tally hidden fields | Trakt |
|---|---|---|
| Setup per form | Add the block each time | Once per site |
| UTMs from an earlier page | Your own script | First-party cookie |
| Source in the CRM | Map via integration | Synced |
| Leads by source | Pivot in a sheet | Leads-by-source overview |
| A form people want to fill in | Same either way | Same either way |
FAQ
How do hidden fields work in Tally?
You add a hidden fields block with field names, and Tally fills each field from a URL parameter of the same name. The visitor never sees them, and the values are stored with the submission.
Can Tally capture UTM parameters?
Yes. Name hidden fields after the UTM parameters and link to the form with the parameters in the URL. For embedded forms, the host page's parameters have to be forwarded to the form.
Why are my Tally hidden fields empty?
Usually the UTMs weren't on the URL the form read. That happens when the visitor arrived on another page first, or when a link to the form had no tags. Check the field names match the parameter names exactly.
How do I send Tally hidden fields to my CRM?
Use Tally's integrations or a webhook, and map each hidden field to a CRM property. Create the properties first and test with a tagged submission.
Is there an easier way to see where Tally submissions come from?
Trakt connects to Tally by webhook and records each submission with the visitor's stored source, so you don't need hidden fields on every form or a script to carry UTMs between pages.
What to do first
Open your Tally form, check it has a hidden fields block, then submit it from your own site with ?utm_source=test. If the submission doesn't show "test", fix the embed before your next campaign.
