I would recommend invoicing for the full year up front. If anyone asks, tell them that this is industry standard. Salesforce, HubSpot and many others do it this way.

If that answer isn't sufficient, here are some others reasons that are beneficial for the customer:

- It simplifies the accounting for the customers - one invoice instead of 6-12
- If you were to buy packaged software, you would pay a huge up front fee and then annual maintenance - we are just asking for the first year
- If you pay monthly, there is no commitment, so there is less incentive to get buy-in from the team and users