It works like older games
Pokemon Scarlet & Violet have a ton of technical quirks, but increasing your box space isn’t one of them. Thankfully, getting more PC box space is one of the simpler aspects of the new generation, as it aligns with the way it’s been done in the past.
Here’s how to easily increase your PC box space.
Put one Pokemon in each existing box to go from eight to 16 boxes
When you start off Pokemon Scarlet & Violet, you’ll have a box cap of eight. That’s not bad at first! Unless you’re catching every single Pokemon you see, you should be fine for a while with eight boxes to hold everything.
Once you’re ready to upgrade though, all you need to do is put one Pokemon in each box. Quit the box system (you may need to save and reload the game), and return. The game will assume each box is being “used,” and will increase your cap to accommodate. At this point you’ll have 16 boxes to work with.
Fill up those 16 boxes to get the new box cap of 32
After that, you can fill those 16 boxes with one Pokemon, and you’ll get a newly minted cap of 32 boxes. Note that this is the end of the line! Don’t try and fill up all 32 boxes, because the game has a hard limit of 32 at launch.
For any other accommodations, you’ll need to integrate Pokemon Home when it’s supported for generation nine.