Australian pricing includes GST. A Tax Invoice/Receipt is issued so you can claim your input tax credits.

Mercumer credits are purchased in bundles of 1000, 2500 or 5000. The larger the bundle size, the lower the cost of each credit. E-mail messages cost 1 credit; SMS messages to Australian mobile phones cost 4 credits.

While there is no monthly fee for using Mercumer, there is a minimum charge of 150 credits each month.
There is no minimum charge for the first month of use.