[GTM glossary](/glossary.md) Confirmed opt-in

Data & Enrichment

# Confirmed opt-in (COI)

Also known as: COI

In short

Confirmed opt-in (COI) is a signup process in which a person submits their email address and then must verify it, usually by clicking a link in a confirmation email, before being added to a mailing list.

The verification step proves the address is real and that its owner wants the emails. COI is a close relative of double opt-in; in practice the two terms are often used for the same flow, though some teams use COI more broadly for any confirmation step.

## How confirmed opt-in works

### 1. The signup

A visitor enters their email on a form, for a newsletter, gated asset, or webinar.

### 2. The confirmation email

The system sends a short message with a unique confirmation link. The contact is stored as pending, not subscribed.

### 3. The confirmation click

When the person clicks, the system marks them as confirmed and logs the timestamp and source. Only then do marketing emails start.

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## Why teams use COI

* **Cleaner lists:** Typos, fake addresses, and bot signups never get confirmed.
* **Better engagement:** People who confirm have shown real interest.
* **Consent evidence:** The confirmation record helps show who agreed, when, and how.
* **Fewer spam complaints:** Recipients expect your messages because they asked for them.

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## Trade-offs

Some people never click the confirmation link, so the list grows more slowly. If the confirmation email lands in spam or looks unfamiliar, good leads are lost. For high-intent forms such as a demo request, many teams skip COI and rely on the form submission plus sales follow-up.

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## Setting it up well

* Send the confirmation immediately so the context is fresh.
* Keep the subject and body short, naming the form the person used.
* Resend once if unconfirmed, then drop the contact.
* Store consent source, timestamp, and the wording shown at signup in the CRM.
* Keep pending contacts out of campaigns until confirmed.

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## Example

Say a team gets 500 newsletter signups in a month and 380 confirm. The team mails the 380 confirmed contacts and ignores the pending ones. Reply and complaint rates stay low because every recipient asked for the email.

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## Confirmed opt-in FAQs

**What is confirmed opt-in (COI)?**

Confirmed opt-in is a signup process where a person must verify their email address, usually by clicking a link in a confirmation email, before being added to a mailing list. It confirms the address is real and the owner wants the messages.

**What is the difference between confirmed opt-in and double opt-in?**

They are usually the same flow: signup, then a confirmation email, then a click. Double opt-in names the two steps, while confirmed opt-in describes the outcome. Some teams use confirmed opt-in more broadly for any verification step.

**Is confirmed opt-in required by law?**

It depends on the region. Most laws require consent or a lawful basis rather than a specific method, but some countries and email providers expect verified consent. Teams should check local rules. This is general information, not legal advice.

**Does confirmed opt-in reduce list size?**

Yes, because some signups never confirm. In exchange the list is cleaner, with fewer fake or mistyped addresses and more engaged recipients. Many teams find the smaller list performs better for deliverability and engagement.

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## More related phrases

* [Do not contact list](/glossary/do-not-contact-list.md)
* [CASL](/glossary/casl.md)
* [Contact database](/glossary/contact-database.md)

## Similar phrases

* [Opt-out](/glossary/opt-out.md)  
An opt-out is a person's request to stop receiving marketing or sales messages, or to stop having their data used, and teams must record and honor it across every system.
* [Email validation](/glossary/email-validation.md)  
Email validation checks whether an email address is correctly formatted and technically able to exist, catching typos and invalid domains before they reach your CRM or sending tool.
* [Data hygiene](/glossary/data-hygiene.md)  
Data hygiene is the ongoing practice of keeping CRM and marketing data clean, accurate, consistent, and usable through regular checks, standards, and ownership.
* [Email deliverability](/glossary/email-deliverability.md)  
Email deliverability is your ability to get emails into recipients’ inboxes instead of spam or being rejected, shaped by reputation, authentication, and content.
* [Double opt-in](/glossary/double-opt-in.md)  
Double opt-in is a two-step consent process where a person first signs up, then confirms by clicking a link in an email, before they are added to a mailing list.