Insurance companies are changing their insurance rates all the time. Sometimes they raise them when there have been a large number of claims, and sometimes they lower rates when they are looking to pick up more clients. What all of this amounts to is that a cheap policy might just represent a market shift or a change in the needs of a particular company. In other words, don’t just give the hairy eyeball to all cheap rates; seek them out. Just make sure that the policy represents your needs well.
In case there are any changes that need to be made in the policy such as address change or any particular changes regarding the automobile or its usage, it could be done by an endorsement by the insurance provider. You need to submit a letter to your insurance provider along with the proof of the changes so that you could obtain the endorsement. There are few endorsements that might charge an extra premium from you.