In most states (South Australia is one key exception) an attorney cannot accept their appointment until a valid enduring power of attorney (EPA) has been executed by the principal who is granting the power in the first place.
Thus any purported acceptance by an attorney before a principal signs the EPA will be invalid.
This said, there is case law to support that a prior invalid acceptance can be remedied by the attorney simply re-executing the document to confirm acceptance of appointment. This approach is possible even where the principal has already lost capacity.
Generally we recommend that attorneys do not sign to accept their appointment until they actually need to rely on the document.
Given attorney documents may never be required, this approach minimises risks with having a fully executed document in existence.
Again, there is case law confirming that an attorney may accept their appointment at any time after a principal has validly executed an EPA, even if the principal has since lost capacity. This is because an EPA is not revoked by a principal’s later loss of capacity.