10DLC Brand/Campaign registration: portal shows "subscription is not eligible" on a qualifying Pay-As-You-Go subscription with US billing

**Summary**

In the Azure portal, under my Communication Services resource, **Telephony and SMS -> Regulatory Documents -> Add**, with Country = United States and Phone number type = **Local**, shows the banner **"Your subscription is not eligible for Brand and Campaign registration"** and the Application type dropdown stays disabled, so 10DLC brand registration cannot be started.

**Why this looks like an eligibility-flag issue rather than a documented restriction**

The documentation ([Apply for 10DLC brand registration and campaign registration](https://learn.microsoft.com/en-us/azure/communication-services/quickstarts/sms/apply-for-ten-digit-long-code)) says 10DLC registration requires a paid subscription type (Pay-As-You-Go, EA, or MCA) with a United States or Canada billing address. My subscription appears to meet both:

- Offer type: Pay-As-You-Go (`PayAsYouGo_2014-09-01`)
- Billing account Sold-To address: United States (Washington state)

Additional observations:

- I have already successfully purchased a US Local number on this subscription, so number-purchase eligibility works
- Selecting Phone number type = **Toll Free** in the same wizard does NOT show the eligibility banner
- The `Microsoft.Communication` resource provider is registered

**Existing reports of the same pattern**

- https://learn.microsoft.com/en-us/answers/questions/5859720/acs-10dlc-brand-campaign-registration-subscription
- https://learn.microsoft.com/en-us/answers/questions/5858184/acs-10dlc-brand-campaign-registration-says-subscri

Both describe qualifying subscriptions showing the same banner, with the answer being that the subscription-level 10DLC eligibility flag needs a backend review.

**Questions**

1. Beyond the documented offer type and billing address requirements, what does the portal check to determine Local/10DLC Brand and Campaign registration eligibility?
2. If a subscription meets the documented requirements but still shows the banner, what is the correct process to get its eligibility reviewed and corrected?

I have an open Azure support request (2607090010001160, Subscription management) that I can reference, and I'm happy to share the subscription ID through a private channel on request.

Start with the Azure portal path Communication Services resource > Telephony and SMS > Regulatory Documents > Add, comparing Local and Toll Free behavior against the linked 10DLC documentation. Review the stated Pay-As-You-Go offer and US billing requirements, then use support request 2607090010001160 for eligibility review. Done means the eligibility decision and correction process are identified, or the documented requirements are clarified.

Written by the indexing model from the issue text.