The document is a useful place to begin
Have the tax year and notice reference ready, and state the part you want explained in plain language. Use (855) 494-5639 for a plain-language explanation of the balance or IRS instruction you do not understand. Keep the source document nearby while avoiding an initial transfer of sensitive tax records.
Clarify what follows the explanation
Ask what review is needed, which records matter, and how a private exchange would be arranged if appropriate. If professional help is proposed, request the responsible person, task boundaries, and fees before authorization. Keep a dated note of an agreed next step separately from an IRS answer or account confirmation. An explanation should identify any further filing, response, or payment task that still needs attention.