A sister city, county, or state relationship is a broad-based, long-term partnership between two communities in two countries. A relationship is officially recognized after the highest elected or appointed official from both communities sign off on an agreement to become sister cities.

A city may have any number of sister cities, with community involvement ranging from a half dozen to hundreds of volunteers. In addition to volunteers, sister city organizations can include representatives from nonprofits, municipal governments, the private sector, and other civic organizations.

Each sister city organization is independent and pursues the activities and thematic areas that are important to them and their community including municipal, business, trade, educational, and cultural exchanges and projects with their sister city.

Frequently Asked Questions

Below you’ll find some of the most commonly asked questions about sister cities and Sister Cities International. If your question isn’t answered below, please contact us at [email protected].

  • How can I find out what my sister cities are?
    Explore our most recent Membership Directory or use our City Search database to find sister city relationships, contact information, and website information for all current members.
  • How do sister city relationships develop?
    Sister city relationships develop from a number of sources, including but not limited to: preexisting mayoral relationships, trade relationships, historical connections, ancestral/demographic connections, expatriate communities, shared geographic/sector challenges, faith-based groups, and personal experiences ranging from study/work abroad to marriages.
  • Who runs sister city organizations and how are they structured?
    All of Sister Cities International’s members are independent organizations and have a number of management structures. Sister city organizations are run by a group of volunteers, representatives from local institutions, the mayor’s office or municipal government, or by some combination of these. Most often sister city organizations are incorporated as 501(c)(3) nonprofits, although the municipal government may have representation or a formal relationship with the group. Many are governed by a board of directors or commission. Organizations are most often organized by committee. Some sister city organizations are run by local institutions, such as a museum, cultural center, or chamber of commerce. Most municipal contacts for sister city organizations are in the office of the mayor, office of tourism/convention and visitors bureau, office of international affairs, office of protocol, or office of economic development.
  • How can I get involved with my local sister city organization?
    Visit our City Search tool search for your community and find the primary contact information for your sister city organization. If you don’t find your city, it means they are not currently a member of the Sister Cities International network. To see if your city has a sister city relationship, do some basic research online or contact the town clerk, mayor’s office, or office of international affairs to see if they can put you in contact with your sister city organization. Most sister city committees have regular meetings that are open to the public.  City Search
  • How can I create a new sister city?
    Sister Cities International recognizes a sister city relationship when mayors or highest elected officials from the two communities sign an agreement to become sister cities, although many cities have their own requirements. You should first contact your local sister city organization and talk to them about their process. Usually a group will first contact the mayor/city government to see if they are open to the possibility of a new relationship. 

    Please see our Cities Seeking Cities page for more information on creating new sister cities. 

  • I am from a city abroad. How can I form a sister city relationship with a city in the United States?
    If you are a municipal employee/elected official, or are working directly with elected officials in your community, then please email us at m[email protected] to let us know you are looking for a partner. Sister Cities International can promote your community to cities around the United States and connect you if there is interest in forming a relationship. 
  • How do I set up a sister city organization for my city?
    Setting up a sister city organization is best done as part of a committee or city-wide group. First, check our Membership Directory and do some web research to see if your city already has an organization. You should not try to start a new sister city or sister city organization without first engaging an existing organization. If your city does not have an organization and you would like to start one, please contact us at [email protected].
  • Do you provide funding for projects?
    Sister Cities International does not provide funding for unsolicited projects or exchanges. However, we do provide funding for dues-paying sister city organizations through grants or other organizations as they are available. These usually have a geographic or programmatic focus and have other requirements depending on the grant. All grant application opportunities are announced on our website and through member updates via emailSign up for our member updates here.
  • Can non-U.S. cities join Sister Cities International?
    Yes, Sister Cities International allows non-U.S. cities to join as Global Members. Global Members can access Sister Cities International’s member services and resources and are listed in our Membership Directory with all of their sister city partnerships worldwide. Visit our membership page for more information.
  • I don’t see one of our sister cities located on Sister Cities International’s directory or website. Why?
    Sister Cities International only lists partnerships of communities which are members of the Sister Cities International network. If you think a city doesn’t appear in our records but should please contact us at [email protected].
  • What is the difference between a “Sister City” and a “Friendship City”?
    The terms “sister city” and “friendship city” sometimes have different meanings. Generally speaking, friendship cities are less formal than sister cities. In some cities, “friendship city” is often used as a first stage in the relationship, and after it is strengthened and the partners are sure they want a long-term relationship they will become “sister cities.”