Can I use the same hardware wallets across multiple accounts on my profile?

Yes, you can customize the availability of the keys on your profile.

It's possible to create multiple accounts on your profile like IRA, personal, business, and trust accounts. You can use your same two keys across all of these accounts; you don't need to buy new hardware wallets for each account. However, you must change your key's availability before it can be used on a new account.

Note: Long-time clients may have edited the BIP32 derivation path on different accounts in the past. This step is no longer necessary, as your keys are now available across all accounts on your profile.

Use the Connections feature to share a key to someone else's account.

How to change your key availability

Sign in to your Unchained account.
Click Keys on the left side of your screen and select the key name you want to change.
Under Account availability, toggle key permissions and click Confirm.
Success! You may now use that key to create a vault in the selected account.