Check the error type. A minor typo may not necessitate prompt action. Language errors in the policy can be ignored if they do not drastically change the meaning or the context. Be sure to read special clauses and terms. A majority of the errors occur in this category.
Call the insurance company and inform them about the problem if it is substantial. There may be a valid case of misrepresentation or misinterpretation. Either way, you will have to resolve the issue as soon as possible. Ask the company to re-issue your insurance policy (or the form) with the error rectified.
Make it a point to correct the coverage limit if it is miquoted and the amount you expected is different. This is vital.
Inquire about the time it will take for the company to fix the error and re-issue an updated policy. If your temporary insurance is about to expire, ask the company to send you the updated policy by fax as well as by priority mail.