Before you can lock a user to a warehouse, go the Admin panel and enable the Warehouses Restricted by Sales Rep? setting under the Warehousing / Order Entry section. 

How to lock a user to a certain warehouse

  1. Go to My Account
  2. Click Manage
  3. Scroll down to the bottom under Members
  4. Select the name of the admin you want to lock the warehouse
  5. In the Accessible Warehouses area, click the checkboxes next to the warehouse you want available
  6. Select Save

Please note that you can also accomplish this for users who are admins, however they would be able to change this setting themselves if desired.

How to set the default warehouse for an individual user

  1. Go to My Account
  2. Click Manage
  3. Scroll down to the bottom under Members
  4. Select the name of the admin you want to lock the warehouse
  5. Select the Primary Warehouse from the dropdown
  6. Select Save