There is no phone number listed on the CP501 letter, only one in the old CP22A letter. The CP501 letter only includes instructions for the payment. Should I call back the CP22A number then?
I also found the following guidance on the TAS>IRS website instructing to write a "Formal Written Protest" for penalties below $25K:
https://www.irs.gov/pub/irs-pdf/p5.pdf
If I write the letter, do I send it to the CP501 address or CP22A address?
