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.
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.
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.
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.
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.
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.
