What happens if the lead tenant doesn’t give me my deposit back?

Here is a bit about the process of deposits and how a lead tenant should act:

Legally, your deposit has to be protected by one of the Government’s recognised schemes. If you have joint tenancy then the deposit will be protected as one amount in the name of a lead tenant (someone nominated by the household). This lead tenant is the one who the deposit scheme administrators will recognise to act on behalf of all of the household.

At the end of the contract the lead tenant (with discussion from the household) can dispute:

the amount returned
how the amount has been divided between tenants

The money is then returned to an account given by the lead tenant. They should then return the money to the remaining tenants.

If lead tenant hasn’t returned your money

You will need to ask for your share of the deposit to be returned by the lead tenant in writing (so you have evidence). If they don’t reply, or only give you some of your deposit, your next step to consider is taking action via the small claims court. If your other housemates have also not received their money, you could all make a joint claim.