Can I use my own domain for the client portal instead of a Kliently URL?

Yes, on the Agency plan. It adds a custom domain plus full white-label, so the portal lives on a URL you own and carries no Kliently branding at all. To a client, it looks and feels entirely like your own product.

If you're a solo freelancer, a branded portal on Starter or Pro is usually plenty — your logo, colour, and name throughout. The custom domain and white-label combination on Agency is built for studios that want clients to never see a vendor name.