All OnSIP phone numbers (DIDs) are enabled for messaging/Multimedia Messaging Service (texting), but OnSIP does not directly provide messaging services. Here are a few third-party vendors that may be able to help; there are many more on the Internet. 

• TextBox- https://www.businesstextbox.com/

• Skipio- https://skipio.com/

• HeyMarket- https://www.heymarket.com/
  

• LiveMessaging- (formerly Heywire) This is a Salesforce application used in conjunction w/their Lightning product: https://www.salesforce.com/products/service-cloud/features/livemessage/
  

• Sense Messaging- https://www.sensehq.com/texting 

Note: Disclaimer - We cannot vouch for the efficacy or availability of any of these services. There is no OnSIP support provided for these services. There is nothing required in the OnSIP Admin portal to enable these services.