This type of loan is designed for people that need a quick cash injection during the month, which they can pay back once their pay checks come in. These loans are usually for small sums that are well below your monthly salary. The amount that you have to pay back is usually at a significantly higher premium than that of a normal loan from a bank, but there is far less red tape in the transaction. Put simply, it is quick but costly.
Lenders would normally ask for proof that you have an income and ask you to provide pay slips, along with proof that your salary was actually deposited into your account, for a certain period of time. This is for them to ensure that you are, in fact, employed and earn said income.
Pay day loans are usually taken when an unexpected emergency comes up. For instance, if your car breaks down in the middle of the month and you cannot afford to fix it, but you cannot get to and from work without it. A quick pay day loan to ensure that you can still do your day to day activities may be your best option, even though the interest rate is exorbitant.