To catch up on missed depreciation, you must make a change in accounting method. However, this is an automatic change; you don’t need IRS approval but do have to follow procedures. Details on how to do this can be found in Rev. Proc. 96-31 (https://www.irs.gov/pub/irs-tege/n96-30.pdf).
An online and phone tax payment system available 24 hours a day. For enrollment information, call 1-800-555-4477, or go to www.eftps.gov.