This is one of the most common questions I get asked. The answer to whether or not you have to sell before you start looking at other houses depends on ☝ thing: finances.
An important question to ask yourself is this: do you need to sell your current house in order to buy (and secure a loan) for a new house?
If the answer is no, then you can go ahead with looking at houses before you put yours on the market.
If the answer is yes, you don’t necessarily need to put your search for a new home on hold until your house has an accepted offer. It will mean we need to be creative when we put an offer on a new home.