Having a passive income that is enough to cover the bills would be really great. This could come from the return on investments such as share dividends, bank account interest, pension income or rental income. All of these will require some investment though and so you will have to plan these well before you decide to give up work. You will need to be confident that you will get a big enough return on them in order to cover all of your expenses and make sure that you will not need to cash them in as this would mean that you would reduce your future income.
Start a Business
You could start a business to generate an income. It can seem really easy, but it is actually hard work and there is no guarantee that it will be a success. It is normal for a business to need lots of investment at the beginning and the owner will not normally pay themselves a salary. Sadly many new businesses fold in the first year or trading, so it is important to make sure that you have a secure business model that will be able to last. This means that it would be wise to get things established before leaving your job.
You could do freelance work to get money coming in. This can sometimes pay more than a regular job but it does depend on the industry that you are working in as sometimes it is much lower paid. There is also no guaranteed work, no holiday or sick pay and often no minimum wage level. It is worth finding out a lot about it before you decide whether you are going to rely on it as an income.
You may need to cut costs as well. This will not be enough to manage with no form of income, as there will always be some things that you will need to pay for. However, it could help you to manage on a lower income if this is something that you are thinking of doing. It can be wise to start doing it as soon as possible so that you get used to managing on less money.
It is probably more realistic to use a mixture of these things in order to finance you leaving a regular job. You may need to cut costs but also find a way of earning some money to top up a passive income. It well worth planning well in advance to make sure that you will be able to manage financially. Consider what you expenses are now and what you could reduce them too then decide how you will cover those costs and whether you think that is a realistic proposal.