Qt is a whole ecosystem which comes with development tools, libraries, frameworks which do not all use the same license options. Often they offer two: an open source license under GPL or LGPL, and a proprietary license.
That said, of course you can use Qt in a company project. All you have to do is abide by the license you choose. Thus you have to make a choice:
use Qt under (usually) GPL royalty-free, and accept that you can only distribute your software under GPL, too.
purchase a proprietary license which allows you to distribute your software under whatever license you like.
Either case: Check the licenses of the individual modules you plan to use (many are available under GPL, some LGPL, maybe there are a few different ones; iirc a proprietary license is available for each). And then make an informed decision. Choose to buy a proprietary license if you are not comfortable to release your Qt-based software under terms of the GPL. The decision process is not different whether you work privately on the software or in a company - yet maybe it impacts the price of the proprietary license option.
Check the license options for each feature of Qt in an overview: https://www.qt.io/product/features
EDIT to add and IANAL: Thus if you want it free-of-charge, it depends:
Your software likely must also remain open source, thus GPL-licensed when developing with Qt. Additionally and especially in the development tool section there then will be a few modules which you cannot use as they have no open source license. However all base packages of the framework seem to be under LGPL. So with some care one might be able to produce a binary which only makes use of LGPL-licensed libraries and thus could be licensed proprietarily provided you abide by the LGPL requirements, especially to allow replacement of those linked libraries to your customers by one of their choice.
