Seems we have to wait for Android Lollipop before we're allowed to write to an arbitrary folder on the external SD card. https://plus.google.com/+JeffSharkey/posts/4kxjY9JFemLhttp://stackoverflow.com/questions/26744842/how-to-use-the-new-sd-card-access-api-presented-for-lollipop Also note that no 3rd party file explorer has write-permissions to an arbitrary folder on the external SD card. I've just tested this with Cheetah Mobile File Manager and ES File Explorer. However, an new app "File Manager" which was appeared after my HTC One M8 Android 4.4.4 update *is* able to write to the SD. I can only presume that this is a "system app" which has the correct permissions.