sipgate is a provider of VoIP / SIP services based in Düsseldorf (Germany).
I've been a SipGate customer since 06/20/2013 - and even though I don't use it soooo often, I think the Düsseldorf boys and girls still do an excellent job, because the SIP telephony is wonderfully integrated - nothing is "tinkered with", the system is well coordinated.
I am primarily a SipGate Basic customer and am happy that I can still be reached via a landline number - even with an answering machine if I don't answer or don't have a SIP client (such as linphone) online at the moment - without having to pay regularly.
In the course of time, however, I have already tried a number of other packages, including more connections, extensions, the fax connection and also the flat rate packages of the provider. All this can be conveniently clicked together in the "Feature Store". When booking one of the flatrate packages, however, the automatic recharge function is directly suggested, which automatically reloads money to the credit account if the balance falls below a certain level. However, the packages can also be easily cancelled at any time via the web interface.