Your organisation does not need to be signed up for you to use Instant GCI.  Instant GCI works on an individual basis, so as long as your employer agrees to your request, you can go ahead.  If they have already allowed other individuals to take part in the scheme, it is likely that the scheme will be advertised internally on either staff noticeboards or the intranet.For Corporate GCI, your organisation will have an GCI code which allows you to access the dedicated portal.  Your HR department or intranet will provide this.