You should always be prepared for hiring any contractor as well as a professional painter. Check this list of some questions you should always ask before signing a contract with professional contractor.
1. Do you have a state business license that allows you to perform such work?
2. Are you or is your business properly insured / can you provide a proof of your insurance?
3. Is your business rated by Better Business Bureau (BBB)?
4. Do you provide free estimates and itemize materials as well as scoop of work?
5. Do you provide written warranty of your work and for how long?
6. Can you provide a list of references?
7. How long will it take to complete this painting project?
8. Are your employees professional painters?
9. What paint brands would you suggest for this job?
10. How do you protect all my belongings during the work?