This was previously answered by Annabel Mario who said: If you buy one license code, you can use UPDF on up to 4 devices — including 2 desktops (so 2 Macs is allowed), plus 2 mobile devices; reinstalling when you replace a device is allowed, and you only need one code if you’re using it on one desktop and one laptop. You can find that answer here: https://appsumo.com/products/updf/questions/running-on-2-computers-1376638/