IRS letters are usually pretty good about telling you what to do if you don't agree with the proposed changes.  What does the letter tell you to do?

Problem is, often the clients like to just send us page 1 of 6 and ignore pages 2-6.  I once had a client fax me pages 1, 3 and 5.  I had to call them and tell them to flip the stack over and fax it again.  Or worse, they ignore the first 3 letters and only send us the letter that says Statutory Notice of Deficiency or Intent to Levy (often insisting that this is the first they're hearing about it).

To answer the question "How can this tax situation be solved?" we need to know which party is your client and what letter you're responding to.