when do you get the XP share?

Question

i have a very low level pokemon and i want to make it higher level when do i get the xp share in pokemon black/white

Answer 1

There are TWO that are available in the game.

• Castelia City (Battle Company)
  >- Reward from the Janitor/President on Battle Company's 55F.
  > He has a Trubbish(Poison) and a Minccino(Normal), both Level 20.

• Gift from the Pokémon Fan Club Chairman
  >- Gift from chairman of the Pokémon Fan Club, if Pokémon shown has gained between 25 and 49 levels since it was met in a Generation V game.

Sources:
Bulbapedia/ Exp. Share
Bulbapedia/ Battle Company
Bulbapedia/ Icirrus City