Unable to update iOS 18.5 on iPhone

What model phone do you have?

• If you have an iPhone 5S or 6/6plus, the highest you can update to is 12.5.7

• If you have an iPhone 6S through 7, or SE 1st generation, you can update to 15.8.4

• If you have an iPhone 8 or X, you can update to 16.7.11

• If you have an iPhone SE (2nd generation or later), or XR through 16, you can update to 18.5

what happens when you try?

does it give an error?

what iphone do you have and what ios is it running now?

have you read

Update your iPhone or iPad - Apple Support

I’ve been having the same issue since the update came out and my phone still can’t accept the update. I have tons of storage space, it’s a 14promax and still it just won’t update.. and it affects my phone carrier system. Half the time my phone doesn’t ring all of a sudden.. It’s really a frustrating update.. needs fixing pronto..