S4C is required to ensure that the content of S4C's television and live streaming services comply with rules set by Ofcom. These are set out in the Ofcom Broadcasting Code and are applicable to all broadcasters in the UK.

Ofcom has a range of statutory powers and responsibilities to ensure the compliance of S4C's services with the relevant regulatory requirements. These include the ability to impose financial penalties on S4C for non-compliance with the statutory requirements. Ofcom can fine S4C up to £250,000.

S4C's on-demand programme services must comply with section 368Q of the Communications Act 2003, and (to the extent that such rules are relevant to S4C), Ofcom's on-demand programme service rules. Ofcom is responsible for regulating S4C's on-demand editorial content, whilst the Advertising Standards Agency (ASA) regulates on-demand advertising content.