Code review:

* Adapted commands identity `LinkAccount` & `ChangeOwnerKey`
  * Added possibility to provide
    * `-a` address of vault account to link
    * `-v` name of vault account to link
  * `-S` (secret_format) doesn't have a default anymore since it conflicts with using `-a` or `-v`
  * Added an error message if none of the params are provided

src/commands/identity.rs

 use crate::*;
 
+use crate::commands::vault::retrieve_account_tree_node_for_name;
 use crate::{
 	commands::revocation::generate_revoc_doc,
 	runtime::runtime_types::{
@@ -63,24 +64,23 @@ pub enum Subcommand {
 	/// Display member count
 	MemberCount,
 	/// Link an account to the identity
-	LinkAccount {
-		/// Secret key format of account to link (seed, substrate)
-		#[clap(short = 'S', long, default_value = SecretFormat::Substrate)]
-		secret_format: SecretFormat,
-		/// Secret of account to link
-		/// most likely different from the one owning the identity
-		#[clap(short, long)]
-		secret: Option<String>,
-		/// Crypto scheme of account to link (sr25519, ed25519)
-		#[clap(short = 'c', long, required = false, default_value = CryptoScheme::Ed25519)]
-		crypto_scheme: CryptoScheme,
-	},
+	LinkAccount(AccountLinkParams),
 	/// Migrate identity to another account
 	/// Change Owner Key
-	ChangeOwnerKey {
+	ChangeOwnerKey(AccountLinkParams),
+}
+
+#[derive(clap::Args, Clone, Debug)]
+pub struct AccountLinkParams {
+	/// SS58 Address of vault account to link
+	#[clap(short, conflicts_with_all=["vault_name","secret_format", "secret", "crypto_scheme"])]
+	address: Option<AccountId>,
+	/// Name of vault account to link
+	#[clap(short = 'v', conflicts_with_all=["secret_format", "secret", "crypto_scheme"])]
+	vault_name: Option<String>,
 	/// Secret key format of account to link (seed, substrate)
-		#[clap(short = 'S', long, default_value = SecretFormat::Substrate)]
-		secret_format: SecretFormat,
+	#[clap(short = 'S', long)]
+	secret_format: Option<SecretFormat>,
 	/// Secret of account to link
 	/// most likely different from the one owning the identity
 	#[clap(short, long)]
@@ -88,7 +88,6 @@ pub enum Subcommand {
 	/// Crypto scheme of account to link (sr25519, ed25519)
 	#[clap(short = 'c', long, required = false, default_value = CryptoScheme::Ed25519)]
 	crypto_scheme: CryptoScheme,
-	},
 }
 
 /// handle identity commands
@@ -156,41 +155,98 @@ pub async fn handle_command(data: Data, command: Subcommand) -> Result<(), GcliE
 					.unwrap()
 			)
 		}
-		Subcommand::LinkAccount {
+		Subcommand::LinkAccount(params) => {
+			async fn perform_link_account(data: Data, keypair: KeyPair) -> Result<(), GcliError> {
+				println!("Trying to make the link");
+				let address = keypair.address();
+				let data = data.fetch_idty_index().await?; // idty index required for payload
+				link_account(&data, address, keypair).await?;
+				Ok(())
+			}
+
+			if let Some(address) = params.address {
+				let key_pair = fetch_vault_keypair_for_target_address(&data, address).await?;
+				perform_link_account(data, key_pair).await?;
+			} else if let Some(vault_name) = params.vault_name {
+				let account_tree_node =
+					retrieve_account_tree_node_for_name(data.connect_db(), &vault_name).await?;
+				let address = account_tree_node.borrow().account.address.0.clone();
+
+				let key_pair = fetch_vault_keypair_for_target_address(&data, address).await?;
+				perform_link_account(data, key_pair).await?;
+			} else if let Some(secret_format) = params.secret_format {
+				let keypair = get_keypair(
 					secret_format,
-			secret,
-			crypto_scheme,
-		} => {
-			let keypair = get_keypair(secret_format, secret.as_deref(), crypto_scheme)?;
+					params.secret.as_deref(),
+					params.crypto_scheme,
+				)?;
 				println!(
 					"target address:'{}' (using crypto-scheme:{})",
 					keypair.address(),
-				<&'static str>::from(crypto_scheme)
+					<&'static str>::from(params.crypto_scheme)
 				);
+				perform_link_account(data, keypair).await?;
+			} else {
+				return Err(GcliError::Input(
+					"One of `address`/`vault_name`/`secret_format`(and optional `secret` & `crypto_scheme`) must be provided".to_string(),
+				));
+			}
+		}
+		Subcommand::ChangeOwnerKey(params) => {
+			async fn perform_change_owner_key(
+				data: Data,
+				keypair: KeyPair,
+			) -> Result<(), GcliError> {
+				println!("Trying to change owner key");
 				let address = keypair.address();
-			data = data.fetch_idty_index().await?; // idty index required for payload
-			link_account(&data, address, keypair).await?;
+				let data = data.fetch_idty_index().await?; // idty index required for payload
+				change_owner_key(&data, address, keypair).await?;
+				Ok(())
 			}
-		Subcommand::ChangeOwnerKey {
+
+			if let Some(address) = params.address {
+				let key_pair = fetch_vault_keypair_for_target_address(&data, address).await?;
+				perform_change_owner_key(data, key_pair).await?;
+			} else if let Some(vault_name) = params.vault_name {
+				let account_tree_node =
+					retrieve_account_tree_node_for_name(data.connect_db(), &vault_name).await?;
+				let address = account_tree_node.borrow().account.address.0.clone();
+
+				let key_pair = fetch_vault_keypair_for_target_address(&data, address).await?;
+				perform_change_owner_key(data, key_pair).await?;
+			} else if let Some(secret_format) = params.secret_format {
+				let keypair = get_keypair(
 					secret_format,
-			secret,
-			crypto_scheme,
-		} => {
-			let keypair = get_keypair(secret_format, secret.as_deref(), crypto_scheme)?;
+					params.secret.as_deref(),
+					params.crypto_scheme,
+				)?;
 				println!(
 					"target address:'{}' (using crypto-scheme:{})",
 					keypair.address(),
-				<&'static str>::from(crypto_scheme)
+					<&'static str>::from(params.crypto_scheme)
 				);
-			let address = keypair.address();
-			data = data.fetch_idty_index().await?; // idty index required for payload
-			change_owner_key(&data, address, keypair).await?;
+				perform_change_owner_key(data, keypair).await?;
+			} else {
+				return Err(GcliError::Input(
+					"One of `address`/`vault_name`/`secret_format`(and optional `secret` & `crypto_scheme`) must be provided".to_string(),
+				));
+			}
 		}
 	};
 
 	Ok(())
 }
 
+async fn fetch_vault_keypair_for_target_address(
+	data: &Data,
+	address: AccountId,
+) -> Result<KeyPair, GcliError> {
+	println!("Trying to retrieve key pair for target address:'{address}'");
+	commands::vault::try_fetch_key_pair(data, address)
+		.await?
+		.ok_or_else(|| GcliError::Input("target vault account not found".to_string()))
+}
+
 // ======================
 
 // TODO derive this automatically