diff --git a/src/slp/utils.js b/src/slp/utils.js
index bd70131..0245ade 100644
--- a/src/slp/utils.js
+++ b/src/slp/utils.js
@@ -1,3 +1,5 @@
+/* eslint-disable no-useless-catch */
+
 // Public npm libraries
 const axios = require('axios')
 const slpParser = require('slp-parser')
@@ -1014,21 +1016,16 @@ class Utils {
 
       return tokenData
     } catch (error) {
-      console.log('decodeOpReturn error: ', error)
-      console.log(`decodeOpReturn error.message: ${error.message}`)
-
-      if (error.response && error.response.data) {
-        // throw error.response.data
-
-        // error.bchApiMessage = error.message
-        // error.message = error.response.data
-        // error.data = error.response.data
-        console.log(
-          `decodeOpReturn error.response.data: ${JSON.stringify(
-            error.response.data
-          )}`
-        )
-      }
+      // Used for debugging
+      // console.log('decodeOpReturn error: ', error)
+      // console.log(`decodeOpReturn error.message: ${error.message}`)
+      // if (error.response && error.response.data) {
+      //   console.log(
+      //     `decodeOpReturn error.response.data: ${JSON.stringify(
+      //       error.response.data
+      //     )}`
+      //   )
+      // }
       throw error
     }
   }
diff --git a/test/unit/fixtures/slp/mock-utils.js b/test/unit/fixtures/slp/mock-utils.js
index c37fd18..a5d672e 100644
--- a/test/unit/fixtures/slp/mock-utils.js
+++ b/test/unit/fixtures/slp/mock-utils.js
@@ -1366,6 +1366,23 @@ const txDetailsSLPNftChild = {
 }
 
 const mock429Error = new Error('Request failed with status code 429')
+mock429Error.response = {
+  status: 429,
+  statusText: 'Too Many Requests',
+  data: {
+    error:
+      'Too many requests. Your limits are currently 100 requests per minute. Increase rate limits at https://fullstack.cash'
+  }
+}
+
+const mock503Error = new Error('Request failed with status code 503')
+mock503Error.response = {
+  status: 503,
+  statusText: 'Service Unavailable',
+  data: {
+    error: 'Some error message'
+  }
+}
 
 module.exports = {
   mockList,
@@ -1399,5 +1416,6 @@ module.exports = {
   whitelist,
   slpdbStatus,
   mockValidateTxidArray,
-  mock429Error
+  mock429Error,
+  mock503Error
 }
diff --git a/test/unit/slp-utils.js b/test/unit/slp-utils.js
index c93cb55..65832dc 100644
--- a/test/unit/slp-utils.js
+++ b/test/unit/slp-utils.js
@@ -495,8 +495,37 @@ describe('#SLP Utils', () => {
 
         assert.fail('Unexpect result')
       } catch (err) {
-        console.log('err: ', err)
-        // assert.include(err.message, 'amount string size not 8 bytes')
+        // console.log('err: ', err)
+
+        assert.property(err, 'message')
+        assert.property(err, 'response')
+        assert.equal(err.response.status, 429)
+        assert.equal(err.response.statusText, 'Too Many Requests')
+        assert.include(err.response.data.error, 'Too many requests')
+      }
+    })
+
+    // 503 means the service is down.
+    it('should throw error when axios returns 503 status', async () => {
+      try {
+        // Mock the call to the REST API
+        sandbox.stub(uut.Utils.axios, 'post').rejects(mockData.mock503Error)
+
+        const txid =
+          'a60a522cc11ad7011b74e57fbabbd99296e4b9346bcb175dcf84efb737030415'
+
+        await uut.Utils.decodeOpReturn(txid)
+        // console.log(`result: ${JSON.stringify(result, null, 2)}`)
+
+        assert.fail('Unexpect result')
+      } catch (err) {
+        // console.log('err: ', err)
+
+        assert.property(err, 'message')
+        assert.property(err, 'response')
+        assert.equal(err.response.status, 503)
+        assert.equal(err.response.statusText, 'Service Unavailable')
+        assert.property(err.response, 'data')
       }
     })
   })