When considering getting a DWA license, you need to firstly think long and hard about the risks involved and whether it is something you truely want to do, it takes a high level of dedication.
To apply for the license you will need to contact your local council, theres no point in going into too much depth because all councils are different but as a general rule you will need:
A locked escape proof room.
A sign on the entrance room of the door warning of what is inside the room.
Locked vivarium also with warning signs.
Relevant handling equipment.
Public liability insurance.
You may need.
A back up handler, alot of times this is the case.
Envenomation protocols, which even if they dont ask for them specifically these are very very important to have.
To be able to turn the light on from either just inside the room or outside before you go in.
A covering letter of proof of being mentored and relevant training.
A double door entry system.
Before they will grant the license, as I mentioned earlier you need to have public liability insurance, there are a few ways to get this, through the people that insure your house (which I found was very expensive and unworkable), a private broker or a specialist company, alot of people use exotics direct I found them to be the best when I looked into it.
Some councils are money grabbers, or just try to put people off put the costs very high, in fact it varies greatly, from £25 in places right up to over £2000 in others.
This is a very brief overview and in no way comprehensive of everything you need to know but it is a start, for someone that wants know the basics. Hope people find it useful.