DANSP50700 - Appeals: Who has a right of appeal: Appeals against varied decisions
Section 11 of the Social Security Contributions (Transfer of Functions, etc.) Act 1999
Article 10 of the Social Security Contributions (Transfer of Functions, etc.) (Northern Ireland) Order 1999 (SI 1999 No 671)
DANSP44100 explains what a varied decision is and when they should be issued.
All those named in the varied decision have a right of appeal against that varied decision if they were named in the original decision and did not appeal against the original decision, see DANSP45400.