Key changes include improvements to the classification and categories of tax defaults, tax geared penalties and the mitigations that apply.
The improvements were necessary because, in relation to the previous appeal mechanism for penalties, a stronger incentive was needed to make a disclosure to the revenue.
The new code also accommodates the stage payment of arrears and more straightforward settlements, where tax default does not result in a loss of money to the exchequer.
The code clarifies what kind of revenue contact triggers the need to make a disclosure and the consequent penalty mitigation available.
The revenue can also apply to court for a determination of penalties where the taxpayer does not agree, within 30 days, with the revenue's opinion or amended opinion).
"No action is required by a tax compliant business," said Joe Duffy of Matheson Ormsbury Prentice. "Obviously, any tax audits of businesses taking place following 1 October 2010 will be carried out in accordance with the guidelines and provisions in the new Code and businesses will need to acquaint themselves with the new Code where selected for tax audit,"
The code, which took effect from October 1, replaces the existing code reflecting changes to the Finance (No 2) Act 2008.
Advisers are not concerned about the update and say it simply ties the changes to the code, since 2002, and the changes to the Finance Act 2008, together in one document.
"It's a case of old wine in a shiny new bottle," said Feargal O'Rourke of PricewaterhouseCoopers.
"The amendments merely bring the Revenue's policies and procedures in line with the new legislation," said Duffy.
