Update phone-number-management-for-united-kingdom.md

UK numbers DASID to PRASID

Author: dbasantes

articles/communication-services/concepts/numbers/phone-number-management-for-united-kingdom.md

@@ -30,6 +30,9 @@ Use the below tables to find all the relevant information on number availability
 
 \** Please refer to [SMS Concepts page](../sms/concepts.md) for supported destinations for this service.
 
+ [!IMPORTANT]
+> Effective **June 30, 2024**, unregistered alphanumeric sender IDs sending messages to UK phone numbers will have its traffic blocked. To prevent this from happening, a [registration application](https://forms.office.com/r/pK8Jhyhtd4) needs to be submitted and be in approved status.
+
 ## Subscription eligibility
 
 To acquire a phone number, you need to be on a paid Azure subscription. Phone numbers can't be acquired by Azure free credits. Also, due to regulatory reasons phone number availability is dependent on your Azure subscription billing location.