This all depends on the value of your next property compared to your current property, and how much equity is currently in your home. If you’re downsizing or have been paying off your current mortgage for a long time, it’s likely that you’ll have enough equity in your home to cover the deposit needed for your new property.
If you’re upsizing, the deposit you need for your new property is going to be bigger than the one you needed for your current home. If you’ve been paying off your mortgage for a while now, you may have enough to cover it from selling your home. If not, you’ll need to find the money to pay the difference.