I've been evaluating which E911 vendor would suit me.
Anveo is good for 12 months or 5 calls to 911, which ever comes first.
Have to say, I just can't believe somehow a person would know or have to count up the number of times 911 might have been called in a year. Mind blowing to me, given the consequence of not having that 6'th call go through, just the same as for non-payment of the subscription.
CallCentric: we do not restrict 911 calling. Meaning, there is no monthly or yearly limit for 911 calls.