Does a 7216 consent need to be signed separately from the engagement letter, and does this apply to both 1040s and business returns?

Consent under 7216 must be voluntary and cannot simply be buried inside the general engagement letter. For 1040s specifically, the consent has to be a separate, distinct document — it cannot be combined into the engagement letter. For business returns, the consent can be wrapped into the engagement letter. The 1040 consent is also very specific about what it must state, per the requirements of the 7216 consent form itself.