Ideally, you need to have an agreement in principle (AIP) in place before taking property viewings. An AIP is a document issued by your lender to state that they are willing to let you borrow from them. This is however based on you supplying sufficient evidence to back up your income and affordability.
AIPs usually last between 30-90 days. If yours expires, you can easily renew it by reaching out to a mortgage broker in Anlaby like us, where we will arrange one within 24 hours for you.