What is the MCPopupSubscribed cookie?
MCPopupSubscribed is an HTTP cookie created by Mailchimp, the email marketing platform many sites use to collect newsletter subscribers. It appears when a site embeds a Mailchimp pop-up signup form (an embedded pop-up or widget generated from a Mailchimp account).
The cookie is set by the Mailchimp script running on the page, not by the host site's own server, once the visitor fills in or interacts with the pop-up form, depending on the form's configuration.
What data it stores
The cookie essentially stores a flag (a yes/no indicator or an associated identifier) noting that the visitor has already subscribed through the Mailchimp pop-up on that site. Mailchimp does not publicly document the exact value format, so it may vary.
The data is read by the Mailchimp script loaded on the page and may be sent to Mailchimp/Intuit servers when the pop-up form checks the visitor's subscription status.
What it is used for
Its practical purpose is to avoid showing the same signup pop-up repeatedly to a visitor who has already subscribed. For site owners, this means a less intrusive experience for existing subscribers; for Mailchimp, it's a way to manage the pop-up widget's state at the browser level.
It is not used for targeted advertising, only for the correct functioning of the signup form.
Does it require consent?
- CookieFix category: preferences (functional).
- Even though its purpose is functional, the cookie is placed by a third-party service (Mailchimp) and is not strictly necessary for the site's core functioning, so under the ePrivacy Directive and GDPR it should generally be treated as requiring prior consent rather than mere disclosure.
- Site owners should list it in their cookie policy, categorize it correctly in the consent banner, and let visitors decline it without blocking access to the main content.
How to block or delete MCPopupSubscribed
A visitor can delete or block this cookie from browser settings (Chrome, Firefox, Edge, Safari) under cookies and site data, either by targeting the Mailchimp domain specifically or by blocking third-party cookies generally.
For site owners, the cookie shouldn't be allowed to set itself before consent is given. A CMP like CookieFix can block the Mailchimp pop-up script until the visitor accepts the preferences category, preventing the cookie from being placed without agreement.
Frequently asked questions
It's a cookie set by Mailchimp through newsletter signup pop-ups, used to remember whether a visitor has already subscribed.
Yes, since it's placed by a third party (Mailchimp) and isn't strictly necessary for the site to work; it should fall under the preferences category and load only after visitor consent.
Its typical duration is 1 year, after which it expires automatically from the browser.
By using a CMP that delays loading the Mailchimp pop-up script until consent is given, or by configuring the form manually so it doesn't load by default.