Yes, absolutely.

As soon as we’ve sent the content over to you and you’ve paid for our services, it’s all yours do with as you see fit.

In the case that we’re link building for you, we can send over the original document, though we’d advise that you not post it anywhere else. We will provide you with evidence that the link as been created, so that you know the work has been completed. But if you were to try and duplicate this content, Google could penalise you for it and the original link will lose all credibility.