If one of your neighbors or friends had a roofing job done, then you can ask them for the recommendations of the roofing contractor that they worked with. You should also make sure that you get to find out if they were satisfied with the work done by roofing companies that was done for them or not.
Another way in which you can be able to check and see if a given roofing contractor is legit or not is by having a look at the website of the roofing company they are working with. Check to see if there is any positive feedback that is coming back from the previous clients that they have worked with before. All companies that are running a reputable business should have a section that has been specifically dedicated to various testimonials from clients that they have worked with previously. It is also better for you to go to the site directly instead of choosing to make use of other third party sites.
The reason as to why it is not advisable to make use of these third party sites is because of the simple fact that they tend to penalize companies that are not making their payments directly. As a result of this, you may not really be able to get the accurate pictures in terms of quality. Therefore, going directly to the site itself should be able to give you a much better picture.
Another thing that you can also do if you are not sure about a given company is by having a look at their business license. You should also check to see if they have proof of warranties and insurance as well as certifications that are needed in the roofing industry. If the company is legitimate, then they should not hesitate to show you these documents. If you find that they are not comfortable to show you the documents or if they are resisting, then it is probably advisable for you to walk away.
As you may have heard, the internet never lies which is why you can always get the information that you are looking for with the right kind of research. You just need to spare some time and make sure that you are able to carefully have a look at all the major areas that may be of concern to you.