---
title: "Opt-In | Sales Glossary"
description: "Explicit consent to receive emails. Required for marketing emails. Learn key concepts, industry benchmarks, and best practices."
canonical: "https://firstsales.io/sales/glossary/opt-in/"
---

[Home](/)/[Glossary](/sales/glossary/)/Opt-In

O, Sales Glossary

# Opt-In

Explicit consent to receive emails. Required for marketing emails.

[Back to glossary](/sales/glossary/)

## What is Opt-In?

Opt-in is the explicit consent a user gives to receive email communications, typically by checking a box, submitting a form, or taking another affirmative action. Opt-in is required for marketing emails under GDPR, CAN-SPAM, and other privacy regulations.

Single opt-in requires one action (submitting a form). Double opt-in (or confirmed opt-in) requires a second confirmation step clicking a link in a verification email to complete subscription. Double opt-in is considered best practice for maintaining list hygiene.

## Why It Matters

Opt-in compliance isn't optional it's legally required. Sending marketing emails without consent violates GDPR (fines up to 20M EUR or 4% of revenue) and CAN-SPAM (penalties up to $50,000 per email). Beyond legal risk, opt-in protects deliverability.

Opt-in also improves engagement. Subscribers who explicitly choose to receive your emails are more interested and engaged than those added without consent. Higher engagement improves open rates, click rates, and deliverability.

## Benchmarks

* **Confirmation rate**: 70-85% of single opt-ins complete double opt-in confirmation
* **Engagement difference**: Double opt-in lists see 30-50% higher engagement than single opt-in
* **Compliance**: Double opt-in is GDPR best practice; single opt-in may not suffice
* **List quality**: Double opt-in lists have 40-60% fewer spam complaints

## Best Practices

1\. **Use double opt-in for marketing lists** \- Require email verification before adding subscribers to marketing lists. This prevents typos, fake signups, and spam traps.

2\. **Make opt-in clear and specific** \- Explain exactly what subscribers will receive and how often. "Weekly sales tips, unsubscribe anytime" beats vague promises.

3\. **Keep opt-in forms simple** \- Only ask for essential information. Each additional field reduces conversion. Name and email are usually sufficient; additional data can be collected later.

4\. **Segment by consent type** \- Track what subscribers opted into. Don't send promotional emails to those who only opted in for newsletters. Respect the specific consent given.

5\. **Honor opt-in scope** \- If someone opts in to a newsletter, don't add them to all email streams. Stay within the scope of their original consent.

## Common Mistakes

* Pre-checking opt-in boxes (illegal in many jurisdictions)
* Not honoring unsubscribe requests promptly
* Adding subscribers to lists beyond their original consent
* Using confusing or misleading opt-in language
* Not maintaining opt-in records to prove consent

## Key Takeaways

* Opt-in is legally required for marketing emails under GDPR and CAN-SPAM
* Double opt-in is best practice for list hygiene and compliance
* Clear, specific opt-in language improves long-term engagement
* Honor the scope of consent; don't expand beyond what subscribers agreed to
* Maintain opt-in records to demonstrate compliance if challenged

## Related Terms

[OObjection HandlingAddressing prospect concerns preventing purchase. LAER framework.View term](/sales/glossary/objection-handling/)[OOnboardingProcess helping new customers successfully adopt product.View term](/sales/glossary/onboarding/)[OOne-Call CloseClosing deal on first interaction. Rare for complex B2B sales.View term](/sales/glossary/one-call-close/)[OOpen RatePercentage of recipients opening email. 25-40% good for cold email.View term](/sales/glossary/open-rate/)

## Put these terms to work, on autopilot

FirstSales scrapes the web for your leads, writes every email, follows up automatically, and books meetings to your calendar. 87% inbox placement from $29/mo.

[Start your AI SDR for $1](https://app.firstsales.io)

Live in 8 minutes. Cancel anytime.