<prompt> Human: I prepared my return on Credit Karma Tax and HRBlock to compare and noticed almost a 300 discrepancy in my refund. After some digging, I found that CK does not include the CA-SDI W2 Box 14 when calculating the state tax deduction. It is only deducting CA State Income Tax W2 Box 17, when it should be adding the two together to maximize your deduction.This only applies to you if you are a California W2 wage earner who is itemizing deductions. If so, its a big miss that can increase your tax liability by hundreds of dollars. The CK site does not have a place where you can manually enter or edit your state taxes, so there is no way to correct it on the customer side at this time. I emailed this information to Credit Karma Tax last Sunday with screenshots of my returns and full details, and have received no response and no correction. Ive seen a few other posts about Credit Karma Tax bugs, so if you are going to use it, be sure to check your return against a more established site or by hand before submitting.TL;DR If you are a California wage earner with itemized deductions - Credit Karma Tax is not deducting CA-SDI when itemizing, a costly error. Everyone should be sure to always double check your returns, especially when using a new service.  <response>: Credit karma is making a lot of mistakes, people shouldnt use it at all 