I have a probleme with Qgis. I would like to change the projection of my shapefile, it’s about caves in my country. The default projection is set to EPSG:3003, I want to change it to wgs84 EPSG:32632. When I do a reprojection file or I change projection in the properties mask I don’t have the correct result. My problem is when I verify the coordinates they are not correct. After days struggling with the different layers in my project, I think I finally understood how SCR works. A1. Project properties >, SCR, you can click on the icon where EPSG is written in the bottom right corner This defines the proprieties of the canvas (the background layer). For exemple, if I wanna display a background map from openlayers plugin (google street,…) I will need to set the project SCR to EPSG:3857. This will indicate to QGIS how it has to project the layer informations. But it will not change the coordinates of the shapefile. This will transform the coordinates of each point into the new coordinate system and save the result in appropriate file. You can also activate the projection ‘on the fly’ (and then ‘OTF’ will appear next to the EPSG projection at the bottom right corner of the main window). This can be useful as it allows QGIS to handle layers with different SCR and to show them simultaneously on the same map without having to manually change the SCR. For me it was tricky as I thought my SCR where identical as I could see all my layers together. Here a visual example to show the difference. I would like to plot a map showing some measurement points in the Jakarta Bay, a grid that created of the Jakarta Bay and in the background a google map: Because my default SCR is EPSG:4326, when I open a new project and try to add an openlayers map such as google physical I obtain an error. So I need to change to EPSG:3857 and then it will work. For the moment I still can’t see the map, but it will appear once I will add an appropriate vector layer. When I add the grid layer it doesn’t show. Looking into the proprieties of the layer indicates me the SCR is EPSG:4326. I don’t know for what reason but this is not the correct SCR for this layer (probably I did a wrong manipulation and changed it in the past). In this case I have to indicate the correct SCR: ‘Define SCR of layer’ and set it to EPSG:32748. After that the layer will appear with the google map. Only now I can permanently change the SCR of the layer: ‘save as’ and choose the same SCR than for the google map (EPSG:3857). If you try to do this manipulation before choosing the original SCR you’ll get an error. When I import my measurement points I have the same problem as before because QGIS chooses by default to set the SCR to EPSG:4326 (you can change that in preferences >, SCR). So I will do again an ‘action 2’. You can right-click on your shapefile in the table of content, choose ‘save as’ and define the projection system that you want as an output. Does this work? Source.