A Zap keeps sending your old Gmail signature because the signature you picked in the Gmail step stays selected as it was when you set up the Zap. Editing the signature in Gmail leaves a published Zap as it is. To switch it: clear the signature field in the Zap's Gmail step, publish, edit the Zap again, select the signature, and publish once more. Repeat for every Zap that sends with it.
The question comes up on the Zapier Community in these words: "I just changed the signature in the gmail account, and I find that the zaps are still using a cached version of the signature." Another user, a year later, put the cost of it plainly: "if I get promoted and have a new title, I don't want to go in and change each of the 73 zaps that use my email signature."
Why Zapier keeps the old signature
Zapier's Gmail "Send Email", "Reply to Email", "Create Draft" and "Create Draft Reply" actions have a signature field ("Add signature default"). Zapier's help describes it as a dropdown that lets you "select a corresponding default signature HTML for an email/alias on your Gmail account."
Users who changed their Gmail signature describe what happens next. The Zap "keeps the old signature until I manually go in to the Zap, edit the zap to select the new signature, and then publish." Back in the editor, "the signature that used to be selected will be unselected, because it no longer exists (since it was edited)." A Zapier staff member answered that automatic updates would be a feature request for the Gmail integration.
So the published Zap holds the signature you chose at setup, and a change in Gmail reaches it only when you choose again.
How to make a Zap use your new Gmail signature
The fix a Zapier Solution Partner posted, which the person asking confirmed with "Thank you, that worked":
- Remove the selected signature in the Zap's Gmail step.
- Publish the Zap.
- Edit the Zap.
- Select the signature again.
- Publish the Zap.
Before you start, check that the new signature is Gmail's default for new emails. Zapier's help says it can only retrieve signatures set under "Signature Defaults" > "For New Emails Use" in Gmail's settings. The Gmail guide shows where that is.
Other Zapier Gmail signature problems
No signature is sent at all
One user testing a Gmail "Send Email" Zap reported: "no signature is being sent out when testing the Send mail(Gmail) zap. Connection tested and OK." Check three things:
- The signature field in the Gmail step has a signature selected.
- That signature is Gmail's default for new emails, for the address the Zap sends from. Zapier's dropdown shows only those.
- The email is a Gmail action. Zapier's Microsoft Outlook "Send Email" has no signature field, so the signature has to go into "Body".
The signature arrives as an attachment in Outlook
A long Zapier Community thread reports the signature "showing as attachment in Outlook. Works fine in Gmail." Zapier staff later announced a partial fix "in the case where the Body Type field is set to HTML." Set the Gmail step's "Body Type" to HTML. If plain-text line breaks then collapse, the same post suggests wrapping the body in <pre> tags.
Two dashes appear above the signature
Users report that Zapier adds two dashes above the signature, even with Gmail set to leave them out. Gmail separates a signature from the message body with two dashes. The fix that worked for a later user: "adding the email signature directly into the body of the email in Zapier. Need to copy in the HTML code, not just copy and paste the signature." Leave the signature field empty when you do this, or the email gets two signatures.
Fix it once: fetch the signature on every run
Pasting the HTML into each Zap trades one stale copy for another. The lasting fix is a step that fetches the current signature each time the Zap runs, so an edit reaches every Zap at once.
Signatoro keeps your signature in one place and serves it to every tool that sends for you:
- Agentic sending. Claude, ChatGPT and other assistants connected to Signatoro's MCP server fetch it with
get_signaturebefore they send. - API fetch. A Zap fetches it with one "Webhooks by Zapier" GET step, and works the same for Gmail and Outlook actions.
- Update once. Change your title on Signatoro and the next run of every Zap sends the new version. In a company, the owner sets the logo, layout and footnote for everyone.
The setup in Zapier:
- Save your signature on Signatoro and click "Generate API key" under "For tools and assistants" on the signature page.
- Add a "Webhooks by Zapier" GET step before the send step, with the URL
https://signatoro.com/api/v1/signature. - Under "Headers", add
Authorizationwith the valueBearer <your key>. Anyone who can edit the Zap can see this value. - In the Gmail or Outlook step, set the body type to HTML, leave the signature field empty, and map the webhook step's
htmlafter the message in "Body".
The n8n, Zapier and Make guide has the same steps for every Zapier email action, and the agent API guide lists the responses.
When ChatGPT writes the email in your Zap
If an AI step writes the body, it may also write a sign-off. One Zapier user found that "most messages are ending with something like 'Best Regards, [Your Name]'" even after telling the model to leave it out. Ask the model for the body only, and cut any sign-off it adds with a Formatter "Split" step before the signature is mapped in. Two signatures on one email covers this in detail, and AI made-up contact details covers the placeholders.
Update your signature once
Make your signature on Signatoro. Every Zap fetches the current version on each run, so a new title reaches all of them.
Frequently asked questions
Why is Zapier still using my old Gmail signature?
The signature field in Zapier's Gmail step keeps the signature that was selected when the Zap was set up, and users report that it stays the same after later edits in Gmail. Clear the field, publish, select the signature again and publish, in every Zap that uses it. A step that fetches the signature on each run avoids the problem.
How do I force Zapier to refresh my Gmail signature?
Remove the selected signature from the Zap's Gmail step, publish the Zap, edit it, select the signature again and publish. Make sure the new signature is set as Gmail's default for new emails first, because Zapier's dropdown only shows signatures chosen under "For New Emails Use".
Why is no signature sent from my Gmail Zap?
Check that a signature is selected in the Gmail step's signature field and that it is Gmail's default for new emails on the sending address. Zapier's help says it can only retrieve signatures set that way. Outlook actions in Zapier have no signature field, so put the signature's HTML in "Body".
Why does my Zapier signature show as an attachment in Outlook?
Users reported that Zapier Gmail emails with a plain-text body showed the signature as an attachment in Outlook, Windows Mail and iOS while Gmail displayed it correctly. Zapier staff said the bug was fixed for emails whose "Body Type" is HTML, so set the Gmail step's "Body Type" to HTML.
Can I update my signature in all my Zaps at once?
Yes, by fetching it on each run. Add a "Webhooks by Zapier" GET step that calls a signature service such as Signatoro and map its html into the email body. An edit made once then reaches every Zap on its next run.
Sources
Checked on 2026-10-07:
- Zapier: Why isn't my signature Gmail displaying in the dropdown?
- Zapier: Send webhooks in Zap workflows
- Google: Troubleshoot issues with Gmail signatures
- Zapier Community: Zapier not using latest Gmail signature, June 20, 2024, with replies to May 2025
- Zapier Community: Troubles adding a signature to Gmail Action -> send email, March 24, 2024
- Zapier Community: Gmail setup signature is an attachment, December 9, 2020
- Zapier Community: Dashed lines in Gmail signature sent through Zapier, April 20, 2023, and How to remove the two dashes from my email signature in Gmail
- Zapier Community: Exclude ChatGPT Sign-off Line, June 6, 2024