Safe contract addresses are determined by the initializer function and a nonce. In order to deploy a Safe to the same address on multiple networks it is important to ensure the following conditions are met:
Same factory address is used on both networks
Same singleton address used on both networks
Same nonce used on both networks
The same initializer payload is used on both networks
This guide includes addresses for the latest v1.4.1 release of Safe. If the Safe you are trying to replicate is an earlier version you must find the old singleton address. This can be found in your original Safe creation transaction (see below)
Factory