We do not charge you for signing up or using the service. The service uses your monthly minutes allowance. As long as you stay within your allowance it will remain free of charge.
HulloMail is available as a free ad-supported app, and also as a yearly/monthly subscription. However, your carrier may charge you for call forwarding if you exceed your monthly call minutes allowance or if you are roaming. Your carrier may also charge you for sending a Hullo, if you exceed your monthly data allowance.
If you download and play a message via the mobile internet you may receive a data charge if you've exceeded you data allowance, or don't have one. When roaming abroad we recommend retrieving messages online whenever you can via my.hullomail.com.