Real Radio Wales has a weekly reach of 434,000 adults, according to the latest Rajar figures.
The station's daytime presenter line-up will not change and breakfast presenters Jagger and Woody will be the first on-air when the national coverage starts at 8am on 4 January.
However, Real Radio is looking for a new breakfast show sponsor to take over from ferry operator Stena Line when the station goes national.
The Real Radio brand targets the 24 to 44 demographic and is also available on FM in central Scotland and across the North West, North East and South and West Yorkshire. It is available on DAB in most major UK regions, and Real Radio Wales is on Sky and Freeview.