diff --git a/src/config/chains.json b/src/config/chains.json
index f243fc5..55d9b08 100644
--- a/src/config/chains.json
+++ b/src/config/chains.json
@@ -57,7 +57,7 @@
         "chainId": "137",
         "label": "Polygon Mainnet",
         "shortName": "Polygon",
-        "code": "poly",
+        "code": "polygon",
         "baseCurrencyName": "MATIC",
         "rpc": "https://polygon-rpc.com/",
         "explorer": "https://polygonscan.com/"
@@ -66,7 +66,7 @@
         "chainId": "80001",
         "label": "Polygon Mumbai",
         "shortName": "Polygon Mumbai",
-        "code": "poly",
+        "code": "polygon",
         "baseCurrencyName": "MATIC",
         "rpc": "https://rpc-mumbai.matic.today",
         "explorer": "https://mumbai.polygonscan.com/"
diff --git a/src/initOrionUnit.ts b/src/initOrionUnit.ts
index 22adc6f..96e2c56 100644
--- a/src/initOrionUnit.ts
+++ b/src/initOrionUnit.ts
@@ -1,27 +1,52 @@
 import OrionUnit from './OrionUnit';
 import { isValidChainId } from './utils';
 import { chains, envs } from './config';
+import { SupportedChainId } from './types';
 
 export default function initOrionUnit(chain: string, env: string) {
-  if (!isValidChainId(chain)) throw new Error(`Chain '${chain}' is not valid.`);
+  if (!(env in envs)) {
+    throw new Error(`Env '${env}' not found. Available environments is: ${Object.keys(envs).join(', ')}`);
+  }
 
-  if (!(env in envs)) throw new Error(`Env '${env}' not found. Available environments is: ${Object.keys(envs).join(', ')}`);
   const envInfo = envs[env];
   const envNetworks = envInfo?.networks;
+  let chainId: SupportedChainId;
 
-  if (!(chain in envNetworks)) {
-    throw new Error(`Chain '${chain}' not found. `
+  if (isValidChainId(chain)) chainId = chain;
+  else {
+    const targetChains = Object
+      .keys(chains)
+      .filter(isValidChainId)
+      .filter((ch) => {
+        const chainInfo = chains[ch];
+        if (!chainInfo) return false;
+        return (chainInfo.chainId in envNetworks)
+          && (chainInfo.code.toLowerCase() === chain.toLowerCase());
+      });
+    if (targetChains.length !== 1) {
+      throw new Error(
+        targetChains.length > 1
+          ? 'Ambiguation detected. '
+            + `Found ${targetChains.length} chain ids [${targetChains.join(', ')}] for chain name '${chain}' in env '${env}'. Expected 1.`
+          : `Chains not found for chain name '${chain}' in env '${env}'.`,
+      );
+    }
+    [chainId] = targetChains;
+  }
+
+  if (!(chainId in envNetworks)) {
+    throw new Error(`Chain '${chainId}' not found. `
           + `Available chains in selected environment (${env}) is: ${Object.keys(envNetworks).join(', ')}`);
   }
 
-  const envNetworkInfo = envNetworks[chain];
-  const chainInfo = chains[chain];
+  const envNetworkInfo = envNetworks[chainId];
+  const chainInfo = chains[chainId];
 
   if (!envNetworkInfo) throw new Error('Env network info is required');
   if (!chainInfo) throw new Error('Chain info is required');
 
   return new OrionUnit(
-    chainInfo.chainId,
+    chainId,
     envNetworkInfo.rpc ?? chainInfo.rpc,
     env,
     envNetworkInfo.api,