Deborah Fiddik, Dorset County Council’s passenger transport development officer, confirmed to councillors the latest update.
She said Damory, which currently runs the Dorset County Council contract for the 7.23am from Bridport to Yeovil and the 5.15pm return journey from Yeovil on Mondays to Fridays during Yeovil College holidays, is ending it on April 5.
Now First has registered these journeys with effect from April 6 as a commercial supplement to the rest of the service which is currently being subsidised by Dorset and Somerset county councils until the end of the Yeovil College summer term.
Ms Fiddik said: “This means that the full Monday to Saturday service is secure until that time.
“The last Sunday service will operate on Sunday, March 28. It should also be noted that there will be no service on public holidays after this date.
“We are exploring alternative solutions for after that date.”
County, district and town Coun Ros Kayes said: “This is great news and I’m especially pleased that a commercial provider has decided to run with this to see whether it's financially viable. I think the message really is now that people must use the service – it really is a case of ‘use it or lose it’ now.
“The more people we get using the 47 the more commercial operators will see it is worthwhile for them as well as being an essential service for those who use it.
“It’s great to see First step up to the mark and take this on.”
Campaigners have been lobbying to save the service since it was threatened last year saying its loss would threaten jobs.
Waytag chairman Peter Smith said: “This route provides a service not only to students and workers along the route but an essential connection for villages along the way. “ Dorset County Council's cabinet agreed at the end of December to continue funding the peak time service, which transports students to and from Yeovil College, jointly with Somerset County Council, until the end of the summer term in June.