For everyone up in arms about this, the terms and conditions have changed since OP posted.
TL:DR children can have accounts with parent/guardian permission.

At least with the acquisition by WOTC, the terms and conditions are as follows (https://company.wizards.com/en/legal/terms)

1.3. Eligibility. Use of the Services is void where prohibited. By registering an account and using the Services, you represent and warrant that: (i) all Registration Data that you submit is truthful and accurate; (ii) you are the age of consent in your country/region or older, or have your parent or guardian's consent, and (iii) your use of the Services will not violate any applicable law or regulation, these Terms, or any other rules, policies, or notices published by Wizards; (iv) you are a "natural person" (corporations, limited liability companies, partnerships and other legal or business entities are not eligible), and (you are a "natural person" (corporations, limited liability companies, partnerships and other legal or business entities are not eligible; and (v) you are not an individual specifically prohibited by Wizards from registering an account or using the Services. Your account may be deleted and your access to the Services terminated without warning if we believe that you are under the age of consent for your country/region and are using the Services without parental/guardian permission. Please note that the purchase or use of certain Services may have different eligibility requirements, including a higher minimum age requirement, as specified in any additional terms governing such Services. You have no property or ownership rights or interest whatsoever in your account. You may not share, sell, transfer, or allow any other person to access your account or Registration Data or offer to do so.

Which to my reading says that if you are a school / library / etc and you wanted to run a D&D club, you should get a signed permission slip from the kids parent to have on file. And then you can create an account for the child.

Also note the restrictions on purchases:

1. Purchase Qualifications; Account Security. To make a purchase on D&D Beyond, you must be a registered D&D Beyond user and in compliance with this Agreement. You acknowledge that you are responsible for maintaining the security of, and restricting access to, your account and password, and you agree to accept responsibility for all purchases and other activities that occur under your account. Wizards sells only to those users who can legally make purchases with a credit card. If you are between the ages of 13 and 18 (or the legal age of majority in your state of residence), you may make purchases on the Service only with the permission of a parent or guardian. Wizards reserves the right to refuse or cancel orders or terminate accounts, at any time in its sole discretion.

You can't make purchases if under 12. If between 13-18 you need parent/guardian permission.

So my two cents would be to buy all of the content you need on the teacher / librarian account along with a Master Subscription for Content Sharing.

Unfortunately that solves none of the forum, chat, data mining, and minor created content/intuectual property (characters and such).  

A group entity account makes these so much worse. As the group would be accountable for actions of individuals. This would require a level of control tools we still don't have access to. (Feature enabling/disabling gated behind a second security option.)

You are correct though that there are options but full security features would be nice. Even adults have mentioned odd forum followers that made them uncomfortable(some tools are available for that but more would be nice)

My 8yo daughter just suggested to me and then registered for an account by signing up through the mobile app and having it request my approval. The kids will be alright.

There is no reason they cannot provide access to children under 13.  There are limits, but those are not egregious.

Ironically, my under-13 year old kids DO have DND Beyond accounts.  One has now turned 13.

I don't know how we managed to do this—works fine on the App, and their Chromebooks.  But not if they try and log in to another account.

So now my younger one has to use an aging Chromebook to play until he turns 13.  Bloody annoying.

Interestingly, this was done before WotC/HASBRO bought DNDBeyond.  However, based on old threads, I don't think there was a change AFTER the purchase . . . this was a policy in place before hand.  So . . . a fun conundrum.  (And yeah, my kids have Nintendo and Microsoft Accounts.  iCloud accounts.  Other games allow Google Sign-in for under 13s.  But not DnDBeyond.  Wish they'd change it!)

Quote from PacerGH >>

There is no reason they cannot provide access to children under 13.  There are limits, but those are not egregious.

Ironically, my under-13 year old kids DO have DND Beyond accounts.  One has now turned 13.

I don't know how we managed to do this—works fine on the App, and their Chromebooks.  But not if they try and log in to another account.

So now my younger one has to use an aging Chromebook to play until he turns 13.  Bloody annoying.

Interestingly, this was done before WotC/HASBRO bought DNDBeyond.  However, based on old threads, I don't think there was a change AFTER the purchase . . . this was a policy in place before hand.  So . . . a fun conundrum.  (And yeah, my kids have Nintendo and Microsoft Accounts.  iCloud accounts.  Other games allow Google Sign-in for under 13s.  But not DnDBeyond.  Wish they'd change it!)

 I haven't checked in a while SO it may no longer be true but one of the main concerns for dndbeyond is some of their "catch all" legal rights. They literally can't make some of the agreements with people under 13 depending on local laws. 

for example if they wanted to use your character build data (based off of personal IP) for marketing, research, community presentations ect....... they cant.   It is just dndbeyond trying to avoid having to deal with the legally impactful implications. For the most part they probably aren't even wrong.

This is just my understanding as I am not an expert.

I am actually an expert, and I draft EULAs and TOSes for clients.

This is not difficult to do.  As I said, there are many companies who already do this for kids under 13 to comply with state, federal, and international laws.

I also have experience on the technical side.  Sequestration of data is not a new thing in the tech industry.  It was forced on the tech industry by Europe more than a decade ago in various forms, and there are plenty of folks who know how to do this.

The only excuses are (1) they didn't think about this when first starting (not uncommon, and understandable, albeit not difficult to know about with a wee bit of research), and (2) they have not spent the time/resources to implement a better approach moving forward (yes, it does take time and resources, but the AMOUNT is VASTLY overstated here and elsewhere; there are basic industry standard data/permission models that are plug-and-play, so it's not reinventing the wheel OR asking your lawyers/coders to do so).

This especially easier if you piggy-back on other login systems like iCloud and Google Accounts, which DnD Beyond already does.  These systems have some built-in processes for handling this kind of thing.

Of course, there is a third (3) excuse—they only want folks who's data they can mine without any restrictions.  This is not an uncommon C-Suite level view and consideration, but it is flawed and myopic.  For one, you cannot mine data without restriction anymore because there are too many different regulatory models restricting it (mostly outside the US) that you must now comply with.  For another, there are always ways to use the data you need and that is helpful.  But C-Suite folks are often unwilling or incapable of knowing how data can and should be used, and instead conceptualize a "hoover it all up approach and process it later" rather than "get only the data we need" approach.

Anyhow, at the end of the day, it is a problem for folks trying to get kids into DnD.  (And my kids are not the only ones trying to get into it, and looking for tools like DnD Beyond to help.)  There are many ways reaching kids can still work within a business model, and fostering play amongst a younger audience so, when they grow older and get their own jobs, they can become a bigger-paying audience, seems like a big opportunity miss.

I just hope they sort it out so I can sort out what to do with my kiddos' accounts.

Quote from PacerGH >>

I am actually an expert, and I draft EULAs and TOSes for clients.

This is not difficult to do.  As I said, there are many companies who already do this for kids under 13 to comply with state, federal, and international laws.

I also have experience on the technical side.  Sequestration of data is not a new thing in the tech industry.  It was forced on the tech industry by Europe more than a decade ago in various forms, and there are plenty of folks who know how to do this.

The only excuses are (1) they didn't think about this when first starting (not uncommon, and understandable, albeit not difficult to know about with a wee bit of research), and (2) they have not spent the time/resources to implement a better approach moving forward (yes, it does take time and resources, but the AMOUNT is VASTLY overstated here and elsewhere; there are basic industry standard data/permission models that are plug-and-play, so it's not reinventing the wheel OR asking your lawyers/coders to do so).

This especially easier if you piggy-back on other login systems like iCloud and Google Accounts, which DnD Beyond already does.  These systems have some built-in processes for handling this kind of thing.

Of course, there is a third (3) excuse—they only want folks who's data they can mine without any restrictions.  This is not an uncommon C-Suite level view and consideration, but it is flawed and myopic.  For one, you cannot mine data without restriction anymore because there are too many different regulatory models restricting it (mostly outside the US) that you must now comply with.  For another, there are always ways to use the data you need and that is helpful.  But C-Suite folks are often unwilling or incapable of knowing how data can and should be used, and instead conceptualize a "hoover it all up approach and process it later" rather than "get only the data we need" approach.

Anyhow, at the end of the day, it is a problem for folks trying to get kids into DnD.  (And my kids are not the only ones trying to get into it, and looking for tools like DnD Beyond to help.)  There are many ways reaching kids can still work within a business model, and fostering play amongst a younger audience so, when they grow older and get their own jobs, they can become a bigger-paying audience, seems like a big opportunity miss.

I just hope they sort it out so I can sort out what to do with my kiddos' accounts.

 Glad to have someone with experience interacting.

I think you kind of hit it with  what may be a mix of all three. They want the data, the effort involved won't outweigh the the benefits, and many of the responsibilities can be pushed off on others as a "safety net". (IE if a kid can just sign up and lie(or someone else takes responsibility) we don't have to give up any thing or take the blame. So let's just not do anything)

I appreciate your input. I am in a similar boat. I just created Google accounts for my kids, specifically so they can create their own characters to play in our family DnD game. The adventures themselves are made through a third party and are specifically designed for younger audiences. I found this thread when I discovered they could not have accounts due to their age restrictions.

Currently, my workaround is that I have all of the characters created under my own account, but doesn't allow me to put them all into a shared campaign. It looks as if I can only add one of my characters to a campaign, which is disappointing. I would definitely pay for a "family plan" account that allowed me to create child accounts.

The nuances of google child accounts aside, at the Master Subscription Tier I create all my kids characters under my account and put them all in a single campaign.  Not sure if it's an option for the Hero tier, but a subscription may be the remedy to do what you want to do.  That said, I think at the free level you can put all your characters into one campaign.

Quote from Uzannesay >>

I appreciate your input. I am in a similar boat. I just created Google accounts for my kids, specifically so they can create their own characters to play in our family DnD game. The adventures themselves are made through a third party and are specifically designed for younger audiences. I found this thread when I discovered they could not have accounts due to their age restrictions.

Currently, my workaround is that I have all of the characters created under my own account, but doesn't allow me to put them all into a shared campaign. It looks as if I can only add one of my characters to a campaign, which is disappointing. I would definitely pay for a "family plan" account that allowed me to create child accounts.

 
You can add as many characters as you want to a campaign. You just need to re-use the join link each time. 

There is no "character per player" limit inside a campaign, and the campaign character limit is 99.

No subs required, either. However each player on a free account can only have 6 characters in total, in campaign or not.