Floorboard repair

Morning.

Considering sanding and restoring floorboards in spare room and have the following question:

Other than replacing a floorboard entirely, are there any other options for filling in holes?

Reason for asking is the floorboards go underneath the skirting boards so replacement would mean removing skirting…

Appreciate it’s probably best practice and easier to remove the skirting but trying to minimise amount of work, cost of new skirting and opportunity for things to go wrong (House not been looked after and it’s been one problem after another so far).

Thanks

Nathan