I used baggage transfers for our two group walks in June and in September.
Jacotrans -
Jacotrans@jacotrans.com - is the one company that seems to have the
Camino Frances covered from Roncesvalles all the way to Galicia after which there is some competition with Xacotrans.
info@xacotrans.com
There are individual taxi owners who pick up and deliver bags in their areas so the drivers change along the route.
Jacotrans charge €7 per bag per stage for up to 6 bags and then on a sliding scale €1 less per bag up to 12 bags. What we did was carry our normal backpacks with raingear, a jacket, blister kits and medication, food and water for the day. We then packed all extra stuff like sandals, washing bags, toiletries, guidebooks etc into a daypack. Our group got together and two people shared one large shopping bag with two daypacks in each bag and shared the cost. Jacotrans have special envelopes that you put your money into and tie onto the bag.
If you send baggage ahead you need to have booked accommodation so that they know where to deliver your bags. If you have all accommodation booked (as we did) you can pay upfront and give them a list of where you'll be staying each day. Then all you do is tie a luggage label onto the bag each day with your name and the next place you'll be staying.
We had absolutely no problems with baggage transfers. The bags are usually collected just after 8am and are delivered by 2pm each day.
The amaWalkers Camino walks cover three sections of the
Camino Frances over three weeks. I can help you with suggestions for accommodation on those three sections if you like and I'm sure with the help of the others on the forum we can find you places to stay in the other villages and towns.
(Our three week walks cost €930 from St Jean and a little less if you start at Roncesvalles).