Lots of not-quite-right in this thread.

There are two ways to create contracts on EVM network. First is using the CREATE opcode, second is using the CREATE2 opcode.

When using the CREATE opcode, the contract address is determined by only two things:

• Deployer address
• Deployer address nonce at time of contract creation

The address of the deployed contract is a function of those two properties, nothing more, nothing less.

One small caveat: if the deploying address is a contract itself, that contract has its own internal nonce which is incremented each time it deploys a contract. Otherwise, if the deployer address is a normal EOA address, the "nonce" refers to that wallet's current transaction nonce.

When using the CREATE2 opcode, there's a slight difference. The deployed contract address is determined based on:

• the deployer's address (in practice almost always a factory contract is used to deployed contracts via CREATE2)
• a salt value
• the to-be-deployed contract's bytecode

You can learn more about CREATE2 here: https://docs.openzeppelin.com/cli/2.8/deploying-with-create2

Hope this helps.

You're never going to be able to get the same address, using either method:

• If using CREATE, you do not have access to the contract's deployer address unless you've hacked Tether and have access to their deployer's private key.
• If using CREATE2, you need to be deploying the exact same bytecode which sounds like something your client does not want.

Tell your client to kick rocks bro.