The purpose of this document is to supplement official ACM documentation on publications with answers to a some questions that come up frequently. Although I serve on the ACM Publications Board, this page is not intended to be an authoritative reference for ACM policy or procedures. Neverthless, it sometimes takes a bit longer to get information out on authoritative channels, and in that spirit, I hope this is helpful.
If you have a question that is not on this list but should be, don't hesitate to contact me at firstname.lastname@example.org.
ACM Open applies to the corresponding author only. So if you want to get Gold Open Access via ACM Open, then your corresponding author needs to be from an ACM Open institution.
Perhaps your corresponding author is set incorrectly. This can happen if your conference management system (e.g. HotCRP) does not explicitly gather the single corresponding author (which is a different concept than HotCRP's multiple "contact authors"). In that case, the corresponding author is often defaulted to the first author, which may not be correct.
If that's the case, you can change it in the ACM e-rights form as follows. The e-rights form has a link to "edit title/author." Clicking this link leads to a popup. The pop-up window shows which author is the corresponding author (there's a green check mark). If you click "Update" by "Authors" then you can change the corresponding author with a radio button (the publishing contact for your conference may be notified about this). Then you can press "Submit" to confirm the changes. Now the corresponding author is whoever you wanted it to be.
If you have trouble with the above, or that does not result in the option to have Gold Open Access despite the corresponding author being from an ACM Open institution, you can also contact ACM production staff (email@example.com. If you have any trouble, please feel free to contact me and I will be happy to help advocate to make sure the right thing happens...making ACM Open succeed is important to all of us on the Publications Board!