Please visit the link below for the latest edition of the guide;
The Best Free SIP Account Providers in 2011 http://snapvoip.blogspot.com/
Keeping up with the tradition of providing the best free SIP account provider list, we have updated the list of Free SIP account providers. Please disregard all other lists.
IPTEL, the the original SER SIP server (Now famous forks, OpenSIPS and Kamailio) and associated services provider has continuously provided free SIP accounts for millions of users and remains our number one favorite. our next continuous Free SIP Provider is SIP2SIP which is a project by AG Projects and PBXs or i-p-tel GmbH, has been providing both free and paid services since we started.
AntiSIP, one of our favorite SIP Account for free providers has also been doing so uninterrupted while many big time providers has gone with the wind. GetonSIP is a new addition to our list and is a service of OnSIP, In addition to free SIP, they also provides free SIP clients for PCs and Android devices.
We have accounts on all the above service providers and have test the service with multiple equipment and softphones.
1. IPTEL.org, IPtel gave me the first taste of SIP a long time ago, at a time when people were asking what VoIP was. Register for an Account here.