After facing some situations where I (or somebody else) had to update a bunch of tags or even bring new ones to OSM, without having to modify geometries themselves, I decided to create a tool that was able to automate the process.

OSM CSV Appender is a simple tool that merges a CSV file into an OSM file. It can be used to import data to OSM, or even to map tags associated to a set of geometries in offline mode that, when ready can be appended to OSM and sent in only one changeset.

There are two ways to join the files. One is matching tags between files and another is matching the id of the geometries.

This tool was developed to be used with JOSM, to prepare OSM files before the appending process. After the process it is used to assess the OSM file quality and to upload the changeset. Now talking about the CSV file, you will need a CSV file editor like LibreOffice Calc and/or GIS programs like Qgis to prepare data and generate CSV files for you.

Although OSM CSV Appender joins files for you, it is very important to assess the quality of the results. To help you with this process the tool also generates a CSV file which contains the usage count of each row in CSV file by each geometry type (node,way and relation).

This tool is documented in OSM CSV Appender on OSM Wiki

Suggestions and feedback of errors are welcome.