Do unverified ACS Phone Numbers have limitations such as character limits?

Question

I am currently working with a customer which is experiencing multiple issues with phone numbers to send text messages in ACS, some issues have been responded in other questions but one more I have and there is less documentation about it is about character limits in the text message body, I noticed that other providers like Twilio allow long messages of over 450 characters, but for some reason, the number the company acquired here, does not send messages unless the character count is 260, I tested this with multiple USA carriers and it works consistent. Microsoft documentation mentions that ACS supports long messages, but I don't understand why it does not work for me and the only explanation I could find based on another question I have made is that since the number is unverified, I can't do it., can you confirm that is the case? Or what can I do to send a little bit longer messages? Thanks

Answer 1

Hi @Anonymous

Thanks for bringing this our attention. correct me if I am wrong, I believe this is the ACS documentation you were referring to?

you should be able to send messages with 260+ character count. Azure Communication Services supports sending and receiving of long messages over SMS. As the doc mentioned, "some wireless carriers or devices may act differently when receiving long messages. We recommend keeping SMS messages to a length of 320 characters and reducing the use of accents to ensure maximum delivery."

But we will check internally with the engineering team to confirm your scenario and will get back to you when we hear
back from them.

Best,
Grace