If you’re happy with the features of your current subscription, but want to increase the number of responses you can collect per month, you can easily do this from your account settings.
If you're subscribed to the Standard plan, you can add 100, 300, 500 or 700 extra responses. If you're subscribed to the Plus plan, you can add 1500, 2000 or 2500 extra responses. If you're subscribed to the PRO plan, you can add 15 000, 25 000 or 50 000 extra responses.
This is how you do it.
Click on the Upgrade button in the top-right corner of the screen. You can either upgrade to a different subscription or add extra seats/responses to your current subscription. Select the options that best suits your needs
From the drop-down menu, select the number of extra responses you want to add. The price will be adjusted accordingly.
When you’re satisfied with the number of extra responses, click Continue and enter your payment details
After the payment has been confirmed, your account will have immediate access to the new number of responses.