Contacting someone when making a change

I’m very new to this. Quite rightly etiquette (and potentially accuracy) dictate that proposed or actual changes should be referred to the creator of an object (sorry if ‘object’ isn’t the correct term!). Can someone please let me know a URL that explains how I can find who the creator of an object is (and how to contact them) after selecting the object?

Go to
Activate Data Layer
Click on the element
The left panel shows the latest version of the object (in the top you can find who did it and in which changeset).
In the bottom of the panel you can find a link to the full history of the element (every changeset).

You could contact the user by private message, or add a comment in the changeset.

Keep in mind that the last user that changed an element is not always who made the mistake.
There are several QA tools that can assist you analyze changesets.

Basically you can go via

where you can find out the OSM id number of an object, and open its history.

There you can see the creator of each element.

Get in contact via OSM internal messaging system.

There is no ownership of objects within OSM, so everyone is entitled to make changes to any element provided (and this is a big provided) that in doing so they improve the map data.

I would recommend contacting a mapper under the following circumstances:

  1. When you believe that the data they entered is incorrect but you yourself have not recently visited the site (and even then it’s possible that something has changed).
  2. When its a relatively inexperienced editor who may not be familiar with various aspects of OSM (e.g., creating duplicate information). In this case be very gentle. Every experienced mapper was a newcomer once.
  3. When you wish to change their tagging, perhaps to something more consistent across an area/country. In this case contact does two things: a) allows original mapper to check if the change is consistent with what they intended; and b) lets them know of a widespread tag convention.

In most cases a changeset discussion is the best place to do this. Do check that the change was made in that changeset (its easy to mis-read the changesets & target a subsequent one). Not only is this discussion visible to other mappers who may have additional knowledge, but comments can be readily viewed using Pascal Neis tool. Also as they are public it (should) encourage people to treat each other respectfully. It may be worth reviewing recent changeset discussions in your area for ideas of what people talk about these exchanges.

Above all follow the Fairhurst dogma “Be bold adding things to OSM, but careful changing them” (a paraphrase).

Thanks for the replies, which were all very helpful, particularly regarding the Data Layer tick box which I hadn’t spotted.