To upgrade go to Biz Setup / Biz Profile. Select the Upgrade Plan section and select the plan that best suit your business needs. If you have a free plan and you want to switch to a regular plan you will be requested to enter a credit card.
You can add additional users, add new credit cards and set your default card.
TIP: Please contact us at firstname.lastname@example.org to select another method of payment (Bank Transfer, check payments or Paypal). This option is only available for annual plans.