Part of the interoperability of Substrate comes from the ability to use the same account on most chains. However, each network has its own address format. For example, the Polkadot format starts with "1", the Kusama format starts with a capital letter, and the generic Substrate format starts with "5".

Polkadot-JS UI

If Polkadot-JS UI is showing the wrong address format for the network you are on, here is how to change it:

1. Navigate to the Settings tab.

2. Select "Default for the connected node" for both "Default icon theme" and "Address prefix":

3. Click "Save."

Your addresses will now always show in the correct format whether you switch to Polkadot, Kusama, or any other chain.

Polkadot Extension

In the Polkadot extension, the address format depends on the chain you have chosen for that account. If you have chosen "Allow on any chain," the format will be the generic Substrate format. However, as discussed above, it will change on Polkadot-JS UI when you switch networks.

If you select a specific chain, the address format will be of that chain, and the account will be available only on that chain.

To change the chain of an account, open the extension and click on the three dots next to the account: