
Here is what happens when you reach the contact limit on your current subscription plan:
Import contacts via sync
If you've enabled the Auto-upgrade option under Settings, Zoho Campaigns automatically upgrades your subscription, allowing you to import contacts via a sync you've created. The upgrade will be based on the number of contacts you are trying to import.
In case you haven’t enabled the Auto-upgrade option under Settings, the sync will stop, and no additional contacts will be imported to Zoho Campaigns upon reaching the contact limit.
Import contacts via files
If you try to import contacts via .csv, .xls, and .xslsx files after the plan limit is reached, you'll be asked for consent each time you try to import the contact. If you give your consent, we will upgrade your plan before importing the contacts.

Note:
The charges will be added up to your next billing cycle.
Switch to pay-as-you-go plan to choose your email credits as per your requirement. Pay-as-you-go allows unlimited contacts.
Log into Zoho Campaigns.
From the Navigation toolbar, click Settings.
Select Subscription under General. You will see your current plan.
Click the Upgrade button in the top-right corner. You will be redirected to Zoho's payments page.
Click the Change Plan.
Select the option to switch to Email-based.
Choose the plan options you want.
Click Upgrade Now.
Switch to pay-as-you-go plan to choose your email credits as per your requirement. Pay-as-you-go allows unlimited contacts.
Log into Zoho Campaigns.
From the Navigation toolbar, click Settings.
Select Subscription under General. You will see your current plan.
Click the Upgrade button in the top-right corner where you can see your current plan.
Click the Cancel my subscription link at the bottom of the page.
Your plan will automatically be changed to a pay-as-you-go plan with zero email credits.
Click Buy Credits.
Choose an email credit plan from the list.
Switch to email-based plan to purchase a certain number of emails you can send. You can have half as many contacts as the number of emails you purchase. All features are available, except for autoresponders and the send email option in workflows.
Log into Zoho Campaigns.
From the Navigation toolbar, click Settings.
Select Subscription under General. You will see your current plan.
the Upgrade button in the top-right corner. You will be redirected to Zoho's payments page.
Click Change Plan under Manage Subscription.
Select the option to switch to email-based and choose the plan options you want.
Click Change.

You can download the invoice using this link.
Before choosing a plan for your organization, you need to know the difference between the plans. Difference between pay-as-you-go plan and the email-based plan are,
The pay-as-you-go plan allows unlimited contacts, while the email-based plan only allows half as many contacts as the number of emails purchased.
The email-based plan is on a recurring payment cycle, meaning that the payment is taken automatically each cycle. The pay-as-you-go plan is not on a recurring cycle.
Purchasing or subscribing to a plan is a one-step process with our payments team if your credit card details are saved. Follow these steps to edit your credit card details on the Payments store.
Click this link
Click Payment Method under Your Store Details.
Click the Change icon and edit your card details in the Payment Method tab.
From here, you can view the available credits in your current plan.
Find below the option to switch to Subscription.
Click Upgrade now
Choose the plan you want.
Click the Settings icon at the top-right of the screen.
Select Subscription under General.
Click the Cancel your subscription plan link.
Click the Change plan option.
Click on Cancel Subscription link at the bottom of the page.
Click Yes. Your plan will automatically be changed to a pay-as-you-go plan with zero email credits.
Log in to Zoho Campaigns.
Click Settings, then select Subscription. You will be redirected to Zoho's payments page. From here, you can easily view all the products you have purchased from Zoho, and manage them on a single platform.
Select a model you prefer—either Subscription plan or Pay-as-you-use.
Choose your plan from the list, then click Upgrade.
Check the plan's price, then review your order and make the payment. A summary of your plan and payment will be displayed.
In case you cannot view the add-on on your Zoho Campaigns application post the approval, please contact support for assistance.


Note: If you've added less than 2000 contacts, then you can send 6000 emails.
The new paid subscription plans are:
Professional plan: This plan is based on the number of contacts in your account. Purchase the plan for a specific number of contacts, then send those contacts unlimited emails, set autoresponders, and use workflows.
Standard plan: This plan is also based on the number of contacts in your account. The major difference between this plan and the professional plan is that some features like autoresponders, dynamic content, and email polls are not available in this plan.
To disable the auto upgrade option for your subscription plans of Zoho Campaigns:
Click the Settings icon.
Click Subscription under General.
Toggle the Auto-upgrade button to disable it.

Note:
If you disable the auto-upgrade option, you won't be allowed to add new contacts. This is likely to affect workflows, your attempts to add new contacts and set up syncs.
In the new version of the free plan the following features will be restricted,
Email attachments
Segmentation
Schedule Email Campaigns
Recipient Timezone based Delivery
Dynamic Content
Email polls
Compare email campaigns
Email campaign archives
Advanced campaigns
Email marketing automation
E-Commerce email marketing
Email limits
Managerial approval
Custom roles
Webhooks
SMS campaigns
All other features are available in this plan. If the users want to access the above features beyond the trial period, they can upgrade to one of the suitable paid plans.
There will be few changes for existing free plan users post the update. Users can add up to 2,000 contacts and send up to 6,000 emails.
The following features will be restricted after May 30, 2022.
Segmentation
Schedule Email Campaigns
Recipient Timezone based Delivery
Dynamic Content
Advanced campaigns
E-Commerce email marketing
However, users will be given an option to switch to trial plan to explore all the features for a period of 14 days.
If they switch to the trial plan, then they will be moved to the new version of free plan.
With the latest pricing update, contact tags are available only under the Professional pricing plan. You will need to upgrade to the Professional plan to create, edit, or assign contact tags.
You can't make use of segments that include advanced fields in the Standard plan. To understand what is meant by 'advanced fields', please refer to this article. You need to upgrade to the Professional plan to use the advanced fields during segment creation. View plan comparison.
A few features will be restricted in the pay-as-you-go plan accounts once you add or reduce number of contacts in your existing plan. This is according to the latest update. Please refer the comparison document to understand these changes.
There will be no changes in pricing for existing users unless you cancel the existing plan and resubscribe to any of the pricing plans. Please refer to the updated pricing plan for the changes in the future.