Ofcom has fined Teletext Limited £225,000 after its public teletext service licence was revoked.
The licence was revoked in January after Teletext had stopped its news and information service on analogue channels in December, even though its licence ran until 2014.
The media regulator said a financial penalty was mandatory in such an event.
Teletext's owner, Daily Mail and General Trust (DMGT), blamed "current economic conditions" for its decision.
Teletext's licence had been scheduled to run until 2014, though Ofcom had indicated it would not be extended beyond that date.
In July last year, DGMT said this had contributed towards its decision to discontinue its public service - a move that put 70 jobs at risk at the unit's base in Chiswick, west London.
Before December, Teletext had broadcast services on the UK's free-to-air commercial channels - ITV, Channel 4 and Five.
Holiday services have continued on Freeview, as have the travel websites Teletextholidays.co.uk, Thisistravel.co.uk and Villarenters.co.uk.
"In deciding to cease providing key elements of the service in December 2009, Teletext committed a serious breach of the obligations in the public teletext service licence," said Ofcom.
"Having given careful consideration to the written and oral representations made, the Committee decided it was appropriate and proportionate in the circumstances to impose a financial penalty."
The BBC has scaled back its Ceefax services but has pledged to provide them until the UK digital switchover is complete.