No. If you already have a method of collecting money from team members (e.g. bank transfer), you can continue using that method.
The benefits of using Teammo to collect payments from your team:
Manage all payments in the one location so you're not tracking multiple payment methods (e.g. bank transfer, cash).
Avoid awkward money conversations because Teammo sends SMS notifications to your team members on your behalf.
Save you time by not having to collect money in person.
If you would like to use Teammo to collect money from your team, you can choose how often you want to request money, and how much you want to collect. All money collected from team members via Teammo is deposited into your bank account. For most major banks, you will receive the money in 1-2 business days.
For more information on the fees for these payments: http://help.teammo.com.au/en/articles/1379344-how-much-does-teammo-cost-for-my-team-to-use.