There is no one-size-fits-all answer to this question since each insurance company has different procedures for checking policy numbers online. However, most insurance companies will have a link or phone number on their website that you can use to contact them and request your policy number. You may need to provide some personal information, such as your name and date of birth, in order to verify your identity. Once you have your policy number, you can typically access your policy information and details online by logging into your account on the insurance company's website.