When you sign up to BOMA you'll see there are two options - monthly or annual.
Monthly Plan:
Signing up to BOMA on a monthly plan gives you the most flexibility. You aren't locked into a contract and can cancel your account at any time.
If you start out on a monthly plan you can upgrade it at any time to an annual plan.
Annual Plan:
Signing up to BOMA on an annual plan offers less flexibility as you are committed for one year. However you save 15% vs the monthly plan.
Further Reading:
How to update your credit card
How to upgrade from a monthly to annual pricing plan
What happens if I cancel my subscription to CCH Business Fitness?