There is no 5th edition rules for Armored Company, only list made under previous versions of the game.
None of them are currently supported by
GW (i.e. no further updates to make them compatible with the current rules) and therefore if you choose to use any of them you'll have to come up with work-arounds yourself for any areas where their rules don't make sense.
If you want to see the older lists you can still find them (for now) on the Australia
GW site (but get it quick because when they switch over to their new style of site this article will likely be gone):
http://oz.games-workshop.com/games/40k/imperialguard/articles/armouredcompany/list.htm
Also, you can find a variant Armored Company army list in the old Imperial Armor Volume #1 from Forgeworld.