Tax engagement letter fundamentals

Here we outline the fundamentals of good tax engagement letter content and suggest provisions that will help minimize legal liability faced by accountants in practice. The advice here will work for most other types of engagement letter also.

Tightening the language used in letters of engagement will help limit your professional liability.

Insurers and solicitors specialising in professional negligence claims will often agree that well drafted letters of engagement are one of the first lines of defence in a professional negligence claim against an accountant. They form the basis of an enforceable contract and should contain:

  • caveats that are unique to the scope of the service provided (e.g. for services outside the scope of the assignment);
  • the amount of risk inherent in the engagement; and
  • references to ethical and professional standards.

Here are some of the fundamental objectives of a well-crafted tax letter of engagement:

  1. Address the letter to the appropriate parties in a formal introductory paragraph. Exclude any taxes not within the scope of the tax return and exclude children of the client or other entities owned by the individual tax client and include the appropriate year or years that are being prepared.
  2. Identify which returns are being prepared, and do not combine multiple returns. (For example, do not include a gift tax return service with an income tax return unless the proper disclaimer language for a gift tax return is included.) The following language is highly recommended.

‘We will prepare your [Year] income tax return. This engagement pertains only to the [Year] tax year, and our responsibilities do not include preparation of any other tax returns that may be due to any tax authority, If we receive specific instructions from you about other taxes or other tax years, these assignments will be the subject of separate engagement letters.’

  1. Deal with the price of the service, payment terms, retainers, additional charges for information received late, additional fees. Clarity and diligence must be adhered to, as many professional liability lawsuits, professional body ethical complaints, and loss of clients have resulted from misunderstanding these provisions.


Too often, vague phrases like the following is used in a standard letter:

‘Our fee for services will be at our standard hourly rate for the personnel assigned to this engagement [or fixed fees to cover other than hourly fee arrangements]. Payment is expected when our services are complete.’’

  1. Consider the following enhancements to the typical clause above:
  • Specify the payment terms more clearly;
  • If you wish, stipulate that a retainer will be required and will be applied toward the final fee and that the retainer is not an estimate of the fee charged for services;
  • Identify when payment is expected;
  • Provide for a termination of services if the fee is not paid in full;
  • Use an additional charge clause for services not originally contemplated; and
  • Include a provision for reimbursement for out-of-pocket expenses such as travel, recorded delivery, etc.
  1. Use a tax checklist for clients to complete and return.


The value of a tax checklist in defending a professional liability claim cannot be overstated. However, many tax advisers complain that their clients do not complete the checklist and often return it unopened. Accountants and tax advisers need to get the client to take responsibility for completing the checklist.


The language used in the engagement letter should establish this responsibility:


‘We will prepare the returns from information which you will furnish to us. It is your responsibility to provide all the information required for the preparation of complete and accurate returns. We will furnish you with questionnaires and/or worksheets as needed to guide you in gathering the necessary information. Your use of such forms will assist us in keeping our fee to a minimum. To the extent we render any accounting and/or bookkeeping assistance, it will be limited to those tasks we deem necessary for preparation of your tax returns’.


For a complete list of our time-saving engagement letter templates for audit, non-audit, tax, grant claims, forensic services and other templates like letters of representation dealing with Brexit and Covid-19, visit our store here.

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