The most reputable tax preparers may request will ask you multiple questions to determine your total income and your qualifications for expenses, deductions, and other items and may ask to see your records and receipts. By doing so, they have your best interest in mind and are trying to help you avoid penalties, interest, or additional taxes that could result from later IRS contacts.

While most tax return preparers are professional and honest, taxpayers can use the following tips to choose a preparer who will offer the best tax fling service for their tax preparation needs.

• Get answers about service fees. Avoid tax preparers who claim they can obtain larger refunds than other preparers, or those who guarantee results or base fees on a percentage of the amount of the refund.
• Think Ahead. Choose a tax preparer you will be able to contact after the tax return is filed and one that will be responsive to your needs.
• Ask for References. Ask questions and get references from clients who have used the tax professional before. Were they satisfied with the tax service received?
• Do Research. Check to see if the tax preparer has any questionable history with the Better Business Bureau, the state’s board of accountancy for CPAs or the state’s bar association for attorneys. Find out if the preparer belongs to a professional organization that requires its members to pursue continuing education and also holds them accountable to a code of ethics.
• Do a preparer’s credentials meet your needs? Are they an Enrolled Agent, Certified Public Accountant or Tax Attorney? Only attorneys, CPAs and enrolled agents can represent taxpayers before the IRS in all matters including tax audits, collection actions and appeals. Other return tax preparers may represent taxpayers only in audits regarding a return they signed as a preparer.

Source: IRS.gov - IRS TAX TIP 2007