Resources Resources IRS IRS Website : https://www.irs.gov/ IRS Customer Service Phone Number : 1-800-829-1040 Fed Refund (Where’s My Refund) : https://www.irs.gov/refunds Fed Payments (Make Payments to IRS) : https://www.irs.gov/payments Tax Withholding Estimator : https://www.irs.gov/individuals/tax-withholding-estimator STATE State Website (CA) : https://www.ftb.ca.gov/ Phone Number : 916-324-0634 State Refund (CA) : https://www.ftb.ca.gov/refund/index.asp State of California (Payments) : https://www.ftb.ca.gov/pay/ Financial Calculators Compound Interest Calculator Return On Investment (ROI) Calculator Tax Equivalent Yield Calculator Investment Income Calculator US Health Savings Account Calculator Rule of 72 Calculator