Can I purchase a one off unlimited 100GB iCloud storage?

You can increase the free 5GB storage level to 50GB, 200GB or 1TB (there is no 100GB level and I don't know what you mean by 'unlimited'). These upgrades require a monthly subscription of $0.99, $2.99 or $9.99 respectively (or equivalent values in different countries). You can't make a one-off payment because this is a continuing use of the server, and there is no annual option.

Testing. Latest reply from Roger had not appeared 32 minutes later. Now okay.

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I've reported the thread to Mandy along with comments about the current slowness of the forums. Now you can 😀

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