diff --git a/.github/workflows/check-existing-prs.yml b/.github/workflows/check-existing-prs.yml
index e10f734..a4fb6aa 100644
--- a/.github/workflows/check-existing-prs.yml
+++ b/.github/workflows/check-existing-prs.yml
@@ -36,8 +36,59 @@ jobs:
           script: |
             const axios = require('axios');
             
+            // Define labels with colors
+            const LABELS = {
+              'balance-ok': {
+                name: 'balance-ok',
+                color: '0e8a16', // green
+                description: 'BTC balance check passed'
+              },
+              'balance-insufficient': {
+                name: 'balance-insufficient',
+                color: 'd93f0b', // red
+                description: 'BTC balance is below required amount'
+              },
+              'invalid-address': {
+                name: 'invalid-address',
+                color: 'fbca04', // yellow
+                description: 'Invalid BTC address or wrong network'
+              }
+            };
+
+            // Create or update labels
+            async function ensureLabel(label) {
+              try {
+                await github.rest.issues.getLabel({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  name: label.name
+                });
+              } catch (error) {
+                if (error.status === 404) {
+                  await github.rest.issues.createLabel({
+                    owner: context.repo.owner,
+                    repo: context.repo.repo,
+                    name: label.name,
+                    color: label.color,
+                    description: label.description
+                  });
+                }
+              }
+            }
+
+            // Ensure all labels exist
+            for (const label of Object.values(LABELS)) {
+              await ensureLabel(label);
+            }
+            
             async function checkBalance(btcAddress) {
               try {
+                // Check if address starts with 'bc1' (mainnet) or 'tb1' (testnet/signet)
+                const isMainnet = btcAddress.startsWith('bc1');
+                if (isMainnet) {
+                  throw new Error('Invalid network: Please use Signet address (tb1) instead of mainnet address (bc1)');
+                }
+
                 console.log(`Checking balance for BTC address: ${btcAddress}`);
                 const response = await axios.get(`https://mempool.space/signet/api/address/${btcAddress}`);
                 const balanceInBTC = response.data.chain_stats.funded_txo_sum / 100000000;
@@ -47,6 +98,12 @@ jobs:
                   hasEnough: balanceInBTC >= 1
                 };
               } catch (error) {
+                if (error.message.includes('Invalid network')) {
+                  throw error;
+                }
+                if (error.response?.status === 400) {
+                  throw new Error('Invalid address or wrong network. Please use a valid Signet (tb1) address');
+                }
                 console.error(`Error checking balance: ${error.message}`);
                 throw error;
               }
@@ -65,14 +122,12 @@ jobs:
               console.log(`\nProcessing PR #${pr.number}: ${pr.title}`);
               
               try {
-                // Get files in this PR
                 const { data: files } = await github.rest.pulls.listFiles({
                   owner: context.repo.owner,
                   repo: context.repo.repo,
                   pull_number: pr.number
                 });
 
-                // Filter for validator JSON files
                 const validatorFiles = files.filter(file => 
                   file.filename.includes('fiamma-testnet-1/bitvm2-staker-validators') && 
                   file.filename.endsWith('.json')
@@ -89,7 +144,6 @@ jobs:
                   console.log(`\nProcessing file: ${file.filename}`);
                   
                   try {
-                    // Get raw content directly from the PR
                     const response = await axios.get(file.raw_url);
                     const content = response.data;
                     
@@ -97,39 +151,65 @@ jobs:
                     try {
                       validatorData = typeof content === 'string' ? JSON.parse(content) : content;
                     } catch (error) {
-                      console.error(`Invalid JSON in ${file.filename}:`, error.message);
+                      const errorMessage = `❌ Invalid JSON format in ${file.filename}: ${error.message}`;
+                      await github.rest.issues.createComment({
+                        owner: context.repo.owner,
+                        repo: context.repo.repo,
+                        issue_number: pr.number,
+                        body: errorMessage
+                      });
                       continue;
                     }
 
                     if (!validatorData.btcAddress) {
-                      console.log(`No BTC address found in ${file.filename}`);
+                      const errorMessage = `❌ No BTC address found in ${file.filename}`;
+                      await github.rest.issues.createComment({
+                        owner: context.repo.owner,
+                        repo: context.repo.repo,
+                        issue_number: pr.number,
+                        body: errorMessage
+                      });
                       continue;
                     }
 
                     console.log(`Checking BTC address: ${validatorData.btcAddress}`);
-                    const result = await checkBalance(validatorData.btcAddress);
-                    
-                    // Add comment to PR with results
-                    await github.rest.issues.createComment({
-                      owner: context.repo.owner,
-                      repo: context.repo.repo,
-                      issue_number: pr.number,
-                      body: `### BTC Balance Check Results for ${file.filename}\n\n` +
-                            `- BTC Address: \`${validatorData.btcAddress}\`\n` +
-                            `- Current Balance: ${result.balance} BTC\n` +
-                            `- Required Balance: 1 BTC\n` +
-                            `- Status: ${result.hasEnough ? '✅ PASSED' : '❌ FAILED'}`
-                    });
-
-                    // Add label based on balance check
-                    const label = result.hasEnough ? 'balance-ok' : 'balance-insufficient';
-                    await github.rest.issues.addLabels({
-                      owner: context.repo.owner,
-                      repo: context.repo.repo,
-                      issue_number: pr.number,
-                      labels: [label]
-                    });
-
+                    try {
+                      const result = await checkBalance(validatorData.btcAddress);
+                      
+                      await github.rest.issues.createComment({
+                        owner: context.repo.owner,
+                        repo: context.repo.repo,
+                        issue_number: pr.number,
+                        body: `### BTC Balance Check Results for ${file.filename}\n\n` +
+                              `- BTC Address: \`${validatorData.btcAddress}\`\n` +
+                              `- Current Balance: ${result.balance} BTC\n` +
+                              `- Required Balance: 1 BTC\n` +
+                              `- Status: ${result.hasEnough ? '✅ PASSED' : '❌ FAILED'}`
+                      });
+
+                      const labelKey = result.hasEnough ? 'balance-ok' : 'balance-insufficient';
+                      await github.rest.issues.addLabels({
+                        owner: context.repo.owner,
+                        repo: context.repo.repo,
+                        issue_number: pr.number,
+                        labels: [LABELS[labelKey].name]
+                      });
+                    } catch (error) {
+                      if (error.message.includes('Invalid network') || error.message.includes('Invalid address')) {
+                        await github.rest.issues.addLabels({
+                          owner: context.repo.owner,
+                          repo: context.repo.repo,
+                          issue_number: pr.number,
+                          labels: [LABELS['invalid-address'].name]
+                        });
+                      }
+                      await github.rest.issues.createComment({
+                        owner: context.repo.owner,
+                        repo: context.repo.repo,
+                        issue_number: pr.number,
+                        body: `❌ Error checking balance for ${file.filename}:\n${error.message}`
+                      });
+                    }
                   } catch (error) {
                     console.error(`Error processing ${file.filename}:`, error);
                   }