Item capacity has officially been increased in Pokémon GO. Niantic has now increased item capacity upgrades, which now allow you to store up to 5,150 items:
Please be aware of your surroundings and follow guidelines from local health authorities when playing Pokémon GO. Upcoming events are subject to change. Be sure to follow Niantic on social media, opt in to receiving push notifications, and subscribe to Niantic’s emails to stay updated.
Source: Pokémon GO on Twitter
Source: Pokemon
