Extra Capacity is a unique, purchasable perk designed specifically for pack animal companions. It is purchased at port in London, from a saddle builder under the Animal Improvement option. Any/all pack animals can be upgraded as desired in a single trip to London, granted the player has the required Funds.
Each pack animal can be "upgraded" up to three times, with each level adding 1 extra capacity slot. Though every level has the same effect, the cost increases with each upgrade:
| Level | Total Added Capacity | Price (Funds) |
|---|---|---|
| 1 | 
|
50 |
| 2 |
|
100 |
| 3 |
|
150 |