A mortgage adviser may seem to be offering a free service and in many cases you will not pay.
Of course nobody works for free and mortgage advisers do like to get paid as there is often a lot of work that is done to help you get your finance approved.
The reason people think that mortgage advisers are free is because mortgage advisers are often paid by the banks and lenders when you successfully get a loan. When this happens the brokers aren’t paid by you, but they are paid a commission by the lender that you end up going with.
In some cases especially with non bank lenders you may be charged a fee by the broker or a fee is specified within the lenders loan offer.
Your mortgage adviser will be able to confirm if they are paid by the bank in which case they will not charge you, or let you know if there will be a fee and what that fee is.