Offer both (monthly billing and annual invoicing) and see which one works better for you. Neither are hard or expensive to setup. Until you have a proven and r

Offer both (monthly billing and annual invoicing) and see which one works better for you. Neither are hard or expensive to setup. Until you have a proven and reliable service that adds value to business owners, I expect most people will opt for monthly billing. It helps with their cash flow and allows them to cancel at an earlier stage. Hence, it is in your interest to try and achieve yearly lockdown whenever possible, even if this means a hefty discount (on the bright side, this also means less admin for you and long-term payment upfront). Once people start using your product, and if it services thier needs, they will be less inclined to leave, especially if they have invested time and energy in setting things ups and creating their workflow around the product.