If I open a second branch in another city, can I run it in the same system but still see how each office is doing on its own?

Yes, you can run more than one office inside the same back office system and still see each one on its own. Most travel back office software has a branch or office level sitting under your main company account, so the bookings, invoices and payments made in one office are grouped together, while you as the owner can still open a single report that covers all of them at once.

The thing that decides whether this actually works is how each booking is tagged at the moment it is made. Normally every member of staff belongs to an office, and anything they book carries that office with it automatically. If your team share logins, or if enquiries come in from the website without being assigned to anyone, those bookings end up sitting outside any branch and your office by office figures will never quite add up. It is much easier to sort that out at the start than to go back and correct it later.

There are limits, and they usually come from the countries involved rather than from the software. A second office in another place may sell in a different currency, may have its own tax treatment, and may have its own agreements with suppliers. Whether the system can hold separate currencies, separate tax settings and separate supplier contracts side by side depends on the product and on the plan you are on, so that is something to confirm with your provider instead of assuming.

Before you commit to the second office, ask to be shown a single branch report and a combined report from a working account, and check that staff logins, sales and supplier costs can all be split by office.