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

If you’re uncertain how to add your integration, you can follow our guide for connecting to Email Service Providers and CRMs.

Next, select MailChimp from the Email Provider dropdown.

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.

Go to MailChimp Account

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

Go to 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.

Copy API Keys

Step 3 – Enter the API Key

In the Campaign 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.

Click Connect with MailChimp

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 MailChimp list

Step 5 – Configure Lead Options (optional)

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

Toggle Double Opt-In

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

Ready to start showing your campaign? See our guide on how to embed your campaigns on your website!


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:

For marketing purposes, most users should use the MailChimp Automation to send a series of emails to new subscribers.

Q: Can I Add MailChimp Groups?

A: Yes! To help provide clarity on implementing MailChimp Groups on your campaign, 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 campaign?

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 campaigns.

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 a campaign’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 campaigns 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
Q: Why is the Phone Number not getting saved in the MailChimp List?

A: Please log into your MailChimp account and navigate to Lists > Select your List > Settings > List fields and *|MERGE|* tags – from this screen you can edit your input fields.

Make sure your phone field has the value of PHONE. After you make that update, you should be good to go.

Phone Field Merge Tag Value