For members in the same council:

Using the online transfer tool is the most efficient way to transfer a Scout’s records from one unit to another. A paper application is not needed. A unit leader in the old unit or the parent can do the transfer. Follow the directions at this link. It will formally transfer the Scout to the new unit and move their advancement records with them:

• Transferring from another unit in the Same Council

For Scouts transferring from one council to another.

Before you register the Scout in the new council follow the directions here:

• Transferring a Scout Between Units in Different Councils

Resources: 

Ensuring a Smooth Scout Transfer