If you need to scan a document, but do not have access to a scanner, you may be able to use your mobile device. Please ensure that your device has a high quality camera and that you have good lighting before you begin.
PDF is the preferred format for returned documents. There are multiple apps available for both iPhone and Android that work well to scan an image to a standard sized PDF file. One example is ClearScanner.
Here are instructions for scanning a document to a PDF file from a mobile device. These instructions use Android and ClearScanner, but the process should be similar on an iPhone.