We will always respect a free trial period. For example, if you upgrade 14 days before your trial expires you won't start paying for 14 days. Monthly Billing: On a monthly plan your Tax Invoice/Statement will usually be generated on the last day of every month. Annual Billing: On an annual plan, you will be charged immediately up-front for the year on the day you upgrade. Any additional fees incurred (e.g. additional users, SMS) will be charged at the end of the month (at the monthly rate of your chosen plan.) There is always the option of pre-paying for additional users at any time, so that you only pay the pro-rata annual rate for the rest of your contract.