Why review each year?
An overall balance can conceal an entry that is disputed, already partly paid, or not yet understood. Separate the periods shown by the actual correspondence and account information. Note the source and date of each figure. If one notice refers to more than one period, preserve its explanation rather than dividing the number using an unsupported assumption.
What facts belong beside the amount?
Identify any relevant return information, adjustment notice, or payment confirmation. Say whether the concern is the explanation of the debt or difficulty paying an understood amount. Those questions can coexist, but they require different review. Keeping a known gap visible is more useful than forcing every year into a complete-looking total before the supporting facts are available.
How should assistance be scoped?
Ask which account periods would be examined and what the review would produce. Discuss how later correspondence or changed amounts would be handled. If an IRS payment process is considered, check its current requirements using the actual account. A working list is preparation for that discussion; it does not approve a payment arrangement, establish an adjustment, or prove that all periods have been resolved.