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HMRC internal manual

Compliance Handbook

Agent operational guidance: dishonest tax agents: establishing dishonest conduct: issuing the conduct notice

The conduct notice must be given to the individual by hand, or posted to their last known private address.

If you have not already issued the Tax agents: Dishonest conduct factsheet (HMRC Website) enclose it with the conduct notice and see CH881300 about giving the human rights message.