Make sure your business owns its domain name, and lock it down

Your domain name controls your website and your email. If you lose it, you lose both. Check who the domain is actually registered to. It's surprisingly common for it to sit in a web designer's or ex-employee's account. Move it into an account your business controls. Then turn on two-factor authentication for the domain registrar, your email and your bank, switch on auto-renew, and keep the card on file up to date. An expired domain can be snapped up within days.