Here's the first major rule: no bags of any kind or size are permitted in the venue.
"There will be no coat check for you to leave your bags at so please leave all clutches, small purses, big purses, handbags, backpacks, and any bags you may have at home," they wrote.
They also added that no cameras would be allowed, though phones are fine, and that security checks would include security wanding and/or pat downs.
They have not specifically said the changes are in response to Manchester, but the Arena's general policy usually permits bags and non-professional cameras into the venue.
Grande will play Spark Arena at 7.30pm on Saturday. Doors open at 6.30pm and fans are advised to arrive early to allow time for security checks.
See their information page for everything you need to know.