Although not a sexy subject, if you’re operating as a SaaS, which most likely you are because most software services are delivered by SaaS today, then you need to have a strong form of a master services agreement, or MSA. That MSA should include a committed term of at least one year and should not include termination for convenience , other you cannot book the revenue and it becomes a month to month deal. Also, add auto renew, better to lock the customer in. The form should also include limitation of liability, disclaimer of warrantees and of course, IP protections etc. Most MSA’s comes with an SLA, which is the support and service level agreement.