Immigration NZ needs more information about your relationship than is contained in a simple marriage certificate. You will be required to submit a variety of documents, including utility bills, pictures, letters, and other paperwork. Usually, the processing time for a Partner of New Zealander Resident visa depends on whether your claim for a genuine and stable relationship is credible and backed up with persuasive evidence. Even a piece of evidence or information could get your application declined (in that case, you could appeal to the Immigration and Protection Tribunal. You can learn which documents are important and which are not by working with an licensed immigration adviser.