Iberia allows 1 checked bag (20 kg, NOT 23kg) + 1 carryon. The carry-on policy is usually not strictly enforced. Additional bags are IIRC 60€.

EasyJet on the other hand charges something reasonable to check your first bag (up to 20kg IIRC) and then charges a ridiculous amount for each additional bag.

Also look into LH on that route, as I think they fly between those two cities as well. There, it's the same policy as IB, but they fly out of T2 so no need to deal with T4.