Yahoo customer service is nowhere close to support team size of giants like Google. For every support query Yahoo encourages you to visit following page: https://io.help.yahoo.com/contact/index?page=home&locale=en_US. On this page you can select type of question that you have and at the end you will get to a page which will ask you if you want to use e-mail or go to community forums. To contact Yahoo select e-mail option and write details of your inquiry. Typically Yahoo responds fast to most of the queries.
Yahoo customer service phone number
Unfortunately Yahoo doesn’t provide a phone number to call. Support is only available via Contact Us page on Yahoo Help website. You can find it here
Even though Yahoo doesn’t publicly states their support phones you can still use some phone numbers that we found to directly reach Yahoo departments: