How to Connect OptinMonster with MailChimp

OptinMonster offers seamless integration with MailChimp email marketing service. Connecting OptinMonster to your MailChimp email list is very easy. Follow our step by step guide on how to connect OptinMonster with your MailChimp account.

What about MailChimp groups? If you have already set up your MailChimp integration, then you can check out our documentation on MailChimp Groups here.
  1. Integrations Tab
  2. Log into Your MailChimp Account
  3. Enter the API Key
  4. Select a List
  5. Configure Lead Options (optional)
  6. FAQs

Step 1 – Integrations Tab

In the optin builder, select the Integrations tab to view the Integrations panel.

Select the Integrations tab in the optin builder to begin connecting your Email Service Provider to OptinMonster.

If this is your first time connecting an integration to your optin you’ll see a “New Integration” item in the Integrations panel of the builder. Select that to begin configuring your integration.

Select the New Integration item to begin connecting your Email Provider to OptinMonster.

Next, select MailChimp from the Email Provider dropdown.

Select the Email Provider from the dropdown list to begin connecting them to your OptinMonster optin.

Step 2 – Log into Your MailChimp Account

To obtain your MailChimp API credentials, log into your MailChimp dashboard and navigate to your Account page from the dropdown menu next to your avatar and name.

Your MailChimp API Keys can be found by selecting the Account link from the dropdown menu that appears under your name in the top right hand corner.

On the Account page, you will need to select the API Keys link under the Extras drop down menu.

Select the Extras link in your MailChimp Account page to navigate to the API Keys

Scroll down the page, and copy the specific API Key you wish to use. You may wish to Create A Key if none are listed or you wish to use a new one.

Your API Keys are listed near the bottom of the page. Select the one you wish to use or create a new key.

Step 3 – Enter the API Key

In the optin builder, paste your API Key into the corresponding field. Don’t forget to add a unique label for easy identification! Then, select the Connect with MailChimp button.

Select the Connect with MailChimp button to finish connecting MailChimp with OptinMonster.

Step 4 – Select a List

OptinMonster will now connect to your MailChimp account and fetch your email lists. Select an email list you want users to subscribe to.

Select a List to add new subscribers to in your MailChimp account.

Step 5 – Configure Lead Options (optional)

You’ll also have the option Enable Double Opt-in? for your optin.

You can configure double opt-in for your campaign in the Lead Options section of the integrations panel.

That’s all, you have successfully connected OptinMonster to your MailChimp account!


Q: How do I send welcome emails to new leads?

A: MailChimp allows you to send a final welcome email to new leads. In order to send final welcome emails:

Q: Can I Add MailChimp Groups?

A: Yes! To help provide clarity on implementing MailChimp Groups on your optin, we’ve created a standalone guide for Adding New Leads to your MailChimp Groups here.

Q: Is it possible for me to add a Phone Field to my optin?

A: Yes! You can add a phone field. Check out How to Capture Phone Numbers with OptinMonster here.

Q: What is the difference between MailChimp (Legacy) and MailChimp?

A: The bad news is that MailChimp is retiring v2.0 (Legacy) of their integration API, and this affects historically created optins.

The good news is that they announced a more powerful v3.0 of their integration API, and it now works seamlessly with OptinMonster.

In order to make sure that this transition does not affect an optin’s conversions, OptinMonster has created a new MailChimp integration.

The process for creating a new MailChimp integration is exactly like the previous one.

What is the new integration called?

We renamed the old integration to MailChimp (Legacy). The new integration is called MailChimp.


To change from MailChimp (Legacy) to the new MailChimp integration, please visit the Integration tab of the optins using MailChimp (Legacy), then replace your existing MailChimp (Legacy) integration with the one now labeled MailChimp.

It’s not necessary to delete the old integration – you can simply change the existing settings to select MailChimp instead.

Once you select MailChimp, you’ll be asked to add your MailChimp API key again, just like you did when you first connected MailChimp to OptinMonster. You can find your API in MailChimp by clicking your username in the upper right corner, then Account, then Extras>API Keys.

What’s the deadline to make the switch?

Unfortunately MailChimp has not provided a clear answer. The MailChimp team said they will stop supporting the [old, legacy] API on December 31st, 2016, but the API will continue to be operational.

So it could be January of 2017 or December of 2018 — there is not a clear answer.

That’s why the OptinMonster team strongly recommends everyone to switch to the new API before December 31st, 2016.

Q: Why am I receiving a “failed to connect” error when trying to connect MailChimp with OptinMonster?

A: This can happen if the API Key you’re using has has maxed out the number of allowed simultaneous connections.

We recommend creating a new API Key to connect to OptinMonster to resolve this issue. If you’re unable to generate a new API Key for some reason, re-trying every 5 minutes until the connection is accepted should also resolve the issue.

Q: Can I receive the IP address of my lead directly into MailChimp?

A: With our native integration we do send over the IP Address of your lead. It should go to MailChimp fields:

  • ip_signup AND / OR
  • ip_opt