diff --git a/test/unit/util_test.js b/test/unit/util_test.js
index 3f46d4e9b..020fad783 100644
--- a/test/unit/util_test.js
+++ b/test/unit/util_test.js
@@ -17,6 +17,52 @@ describe('util', function() {
     this.sinon.restore()
   })
 
+  describe('addressSummary', function() {
+    it('should add case-sensitive checksum', function() {
+      var address = '0xfdea65c8e26263f6d9a1b5de9555d2931a33b825'
+      var result = util.addressSummary(address)
+      assert.equal(result, '0xFDEa65C8...b825')
+    })
+  })
+
+  describe('isValidAddress', function() {
+    it('should allow 40-char non-prefixed hex', function() {
+      var address = 'fdea65c8e26263f6d9a1b5de9555d2931a33b825'
+      var result = util.isValidAddress(address)
+      assert.ok(result)
+    })
+
+    it('should allow 42-char non-prefixed hex', function() {
+      var address = '0xfdea65c8e26263f6d9a1b5de9555d2931a33b825'
+      var result = util.isValidAddress(address)
+      assert.ok(result)
+    })
+
+    it('should not allow less non hex-prefixed', function() {
+      var address = 'fdea65c8e26263f6d9a1b5de9555d2931a33b85'
+      var result = util.isValidAddress(address)
+      assert.ok(!result)
+    })
+
+    it('should not allow less hex-prefixed', function() {
+      var address = '0xfdea65ce26263f6d9a1b5de9555d2931a33b85'
+      var result = util.isValidAddress(address)
+      assert.ok(!result)
+    })
+
+    it('should recognize correct capitalized checksum', function() {
+      var address = '0xFDEa65C8e26263F6d9A1B5de9555D2931A33b825'
+      var result = util.isValidAddress(address)
+      assert.ok(result)
+    })
+
+    it('should recognize incorrect capitalized checksum', function() {
+      var address = '0xFDea65C8e26263F6d9A1B5de9555D2931A33b825'
+      var result = util.isValidAddress(address)
+      assert.ok(!result)
+    })
+  })
+
   describe('numericBalance', function() {
 
     it('should return a BN 0 if given nothing', function() {
diff --git a/ui/app/account-detail.js b/ui/app/account-detail.js
index 263e48441..489392473 100644
--- a/ui/app/account-detail.js
+++ b/ui/app/account-detail.js
@@ -13,6 +13,7 @@ const Identicon = require('./components/identicon')
 const EtherBalance = require('./components/eth-balance')
 const transactionList = require('./components/transaction-list')
 const ExportAccountView = require('./components/account-export')
+const ethUtil = require('ethereumjs-util')
 
 module.exports = connect(mapStateToProps)(AccountDetailScreen)
 
@@ -110,7 +111,7 @@ AccountDetailScreen.prototype.render = function() {
           }),
 
           h('i.fa.fa-clipboard.fa-md.cursor-pointer.color-orange', {
-            onClick: () => copyToClipboard(selected),
+            onClick: () => copyToClipboard(ethUtil.toChecksumAddress(selected)),
           }),
 
         ]),
@@ -133,7 +134,7 @@ AccountDetailScreen.prototype.render = function() {
           }, 'SEND ETH'),
 
         ]),
-      
+
       ]),
 
       // subview (tx history, pk export confirm)
diff --git a/ui/app/send.js b/ui/app/send.js
index 67dd15f81..044311b94 100644
--- a/ui/app/send.js
+++ b/ui/app/send.js
@@ -219,7 +219,7 @@ SendTransactionScreen.prototype.onSubmit = function() {
     return this.props.dispatch(actions.displayWarning(message))
   }
 
-  if ((recipient.length !== 42 && !txData) || (!recipient && !txData)) {
+  if ((util.isValidAddress(recipient) && !txData) || (!recipient && !txData)) {
     var message = 'Recipient address is invalid.'
     return this.props.dispatch(actions.displayWarning(message))
   }
diff --git a/ui/app/util.js b/ui/app/util.js
index 0f3f191aa..d8a0313ea 100644
--- a/ui/app/util.js
+++ b/ui/app/util.js
@@ -21,6 +21,8 @@ for (var currency in valueTable) {
 module.exports = {
   valuesFor: valuesFor,
   addressSummary: addressSummary,
+  isAllOneCase: isAllOneCase,
+  isValidAddress: isValidAddress,
   numericBalance: numericBalance,
   parseBalance: parseBalance,
   formatBalance: formatBalance,
@@ -42,7 +44,19 @@ function valuesFor(obj) {
 }
 
 function addressSummary(address) {
-  return address ? address.slice(0,2+8)+'...'+address.slice(-4) : '...'
+  var checked = ethUtil.toChecksumAddress(address)
+  return checked ? checked.slice(0,2+8)+'...'+checked.slice(-4) : '...'
+}
+
+function isValidAddress(address) {
+  var prefixed = ethUtil.addHexPrefix(address)
+  return isAllOneCase(prefixed) && ethUtil.isValidAddress(prefixed) || ethUtil.isValidChecksumAddress(prefixed)
+}
+
+function isAllOneCase(address) {
+  var lower = address.toLowerCase()
+  var upper = address.toUpperCase()
+  return address === lower || address === upper
 }
 
 // Takes wei Hex, returns wei BN, even if input is null