diff --git a/homeassistant/components/sensor/currencylayer.py b/homeassistant/components/sensor/currencylayer.py
index b1686e8302d..71d49cafc46 100644
--- a/homeassistant/components/sensor/currencylayer.py
+++ b/homeassistant/components/sensor/currencylayer.py
@@ -1,24 +1,34 @@
-"""Support for currencylayer.com exchange rates service."""
+"""
+Support for currencylayer.com exchange rates service.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/sensor.currencylayer/
+"""
 from datetime import timedelta
 import logging
+
 import requests
 import voluptuous as vol
-import homeassistant.helpers.config_validation as cv
+
 from homeassistant.components.sensor import PLATFORM_SCHEMA
+from homeassistant.const import (
+    CONF_API_KEY, CONF_NAME, CONF_BASE, CONF_QUOTE, ATTR_ATTRIBUTION)
 from homeassistant.helpers.entity import Entity
 from homeassistant.util import Throttle
-from homeassistant.const import (CONF_API_KEY, CONF_NAME, CONF_PAYLOAD)
+import homeassistant.helpers.config_validation as cv
 
-_RESOURCE = 'http://apilayer.net/api/live'
 _LOGGER = logging.getLogger(__name__)
-# Return cached results if last scan was less then this time ago.
-MIN_TIME_BETWEEN_UPDATES = timedelta(hours=2)
-CONF_BASE = 'base'
-CONF_QUOTE = 'quote'
+_RESOURCE = 'http://apilayer.net/api/live'
+
+CONF_ATTRIBUTION = "Data provided by currencylayer.com"
+
 DEFAULT_BASE = 'USD'
 DEFAULT_NAME = 'CurrencyLayer Sensor'
+
 ICON = 'mdi:currency'
 
+MIN_TIME_BETWEEN_UPDATES = timedelta(hours=2)
+
 PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
     vol.Required(CONF_API_KEY): cv.string,
     vol.Required(CONF_QUOTE): vol.All(cv.ensure_list, [cv.string]),
@@ -28,25 +38,22 @@ PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
 
 
 def setup_platform(hass, config, add_devices, discovery_info=None):
-    """Setup the Currencylayer sensor."""
-    payload = config.get(CONF_PAYLOAD)
-    rest = CurrencylayerData(
-        _RESOURCE,
-        config.get(CONF_API_KEY),
-        config.get(CONF_BASE, 'USD'),
-        payload
-    )
-    response = requests.get(_RESOURCE, params={'source':
-                                               config.get(CONF_BASE, 'USD'),
-                                               'access_key':
-                                               config.get(CONF_API_KEY),
-                                               'format': 1}, timeout=10)
+    """Set up the Currencylayer sensor."""
+    base = config.get(CONF_BASE)
+    api_key = config.get(CONF_API_KEY)
+    parameters = {
+        'source': base,
+        'access_key': api_key,
+        'format': 1,
+    }
+
+    rest = CurrencylayerData(_RESOURCE, parameters)
+
+    response = requests.get(_RESOURCE, params=parameters, timeout=10)
     sensors = []
     for variable in config['quote']:
-        sensors.append(CurrencylayerSensor(rest, config.get(CONF_BASE, 'USD'),
-                                           variable))
-    if "error" in response.json():
-        _LOGGER.error("Check your Currencylayer API")
+        sensors.append(CurrencylayerSensor(rest, base, variable))
+    if 'error' in response.json():
         return False
     else:
         add_devices(sensors)
@@ -66,7 +73,7 @@ class CurrencylayerSensor(Entity):
     @property
     def name(self):
         """Return the name of the sensor."""
-        return str(self._base) + str(self._quote)
+        return '{} {}'.format(self._base, self._quote)
 
     @property
     def icon(self):
@@ -78,12 +85,20 @@ class CurrencylayerSensor(Entity):
         """Return the state of the sensor."""
         return self._state
 
+    @property
+    def device_state_attributes(self):
+        """Return the state attributes of the sensor."""
+        return {
+            ATTR_ATTRIBUTION: CONF_ATTRIBUTION,
+        }
+
     def update(self):
-        """Update current conditions."""
+        """Update current date."""
         self.rest.update()
         value = self.rest.data
         if value is not None:
-            self._state = round(value[str(self._base) + str(self._quote)], 4)
+            self._state = round(
+                value['{}{}'.format(self._base, self._quote)], 4)
 
 
 # pylint: disable=too-few-public-methods
@@ -91,24 +106,20 @@ class CurrencylayerData(object):
     """Get data from Currencylayer.org."""
 
     # pylint: disable=too-many-arguments
-    def __init__(self, resource, api_key, base, data):
+    def __init__(self, resource, parameters):
         """Initialize the data object."""
         self._resource = resource
-        self._api_key = api_key
-        self._base = base
+        self._parameters = parameters
         self.data = None
 
     @Throttle(MIN_TIME_BETWEEN_UPDATES)
     def update(self):
         """Get the latest data from Currencylayer."""
         try:
-            result = requests.get(self._resource, params={'source': self._base,
-                                                          'access_key':
-                                                          self._api_key,
-                                                          'format': 1},
-                                  timeout=10)
-            if "error" in result.json():
-                raise ValueError(result.json()["error"]["info"])
+            result = requests.get(
+                self._resource, params=self._parameters, timeout=10)
+            if 'error' in result.json():
+                raise ValueError(result.json()['error']['info'])
             else:
                 self.data = result.json()['quotes']
                 _LOGGER.debug("Currencylayer data updated: %s",
diff --git a/homeassistant/components/sensor/fixer.py b/homeassistant/components/sensor/fixer.py
index c8fe3b06c4e..a9f53811c59 100644
--- a/homeassistant/components/sensor/fixer.py
+++ b/homeassistant/components/sensor/fixer.py
@@ -10,7 +10,7 @@ from datetime import timedelta
 import voluptuous as vol
 
 from homeassistant.components.sensor import PLATFORM_SCHEMA
-from homeassistant.const import CONF_NAME, ATTR_ATTRIBUTION
+from homeassistant.const import (CONF_NAME, ATTR_ATTRIBUTION, CONF_BASE)
 from homeassistant.helpers.entity import Entity
 from homeassistant.util import Throttle
 import homeassistant.helpers.config_validation as cv
@@ -24,7 +24,6 @@ ATTR_EXCHANGE_RATE = 'Exchange rate'
 ATTR_TARGET = 'Target currency'
 
 CONF_ATTRIBUTION = "Data provided by the European Central Bank (ECB)"
-CONF_BASE = 'base'
 CONF_TARGET = 'target'
 
 DEFAULT_BASE = 'USD'
diff --git a/homeassistant/components/sensor/openexchangerates.py b/homeassistant/components/sensor/openexchangerates.py
index b4e7033bcc0..d0e3ffb2cdd 100644
--- a/homeassistant/components/sensor/openexchangerates.py
+++ b/homeassistant/components/sensor/openexchangerates.py
@@ -11,7 +11,8 @@ import requests
 import voluptuous as vol
 
 from homeassistant.components.sensor import PLATFORM_SCHEMA
-from homeassistant.const import (CONF_API_KEY, CONF_NAME, CONF_PAYLOAD)
+from homeassistant.const import (
+    CONF_API_KEY, CONF_NAME, CONF_BASE, CONF_QUOTE, ATTR_ATTRIBUTION)
 import homeassistant.helpers.config_validation as cv
 from homeassistant.helpers.entity import Entity
 from homeassistant.util import Throttle
@@ -19,8 +20,7 @@ from homeassistant.util import Throttle
 _LOGGER = logging.getLogger(__name__)
 _RESOURCE = 'https://openexchangerates.org/api/latest.json'
 
-CONF_BASE = 'base'
-CONF_QUOTE = 'quote'
+CONF_ATTRIBUTION = "Data provided by openexchangerates.org"
 
 DEFAULT_BASE = 'USD'
 DEFAULT_NAME = 'Exchange Rate Sensor'
@@ -36,20 +36,24 @@ PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
 
 
 def setup_platform(hass, config, add_devices, discovery_info=None):
-    """Setup the Open Exchange Rates sensor."""
+    """Set up the Open Exchange Rates sensor."""
     name = config.get(CONF_NAME)
     api_key = config.get(CONF_API_KEY)
     base = config.get(CONF_BASE)
     quote = config.get(CONF_QUOTE)
-    payload = config.get(CONF_PAYLOAD)
 
-    rest = OpenexchangeratesData(_RESOURCE, api_key, base, quote, payload)
-    response = requests.get(_RESOURCE, params={'base': base,
-                                               'app_id': api_key},
-                            timeout=10)
+    parameters = {
+        'base': base,
+        'app_id': api_key,
+    }
+
+    rest = OpenexchangeratesData(_RESOURCE, parameters, quote)
+    response = requests.get(_RESOURCE, params=parameters, timeout=10)
+
     if response.status_code != 200:
         _LOGGER.error("Check your OpenExchangeRates API key")
         return False
+
     rest.update()
     add_devices([OpenexchangeratesSensor(rest, name, quote)])
 
@@ -77,7 +81,10 @@ class OpenexchangeratesSensor(Entity):
     @property
     def device_state_attributes(self):
         """Return other attributes of the sensor."""
-        return self.rest.data
+        attr = self.rest.data
+        attr[ATTR_ATTRIBUTION] = CONF_ATTRIBUTION
+
+        return attr
 
     def update(self):
         """Update current conditions."""
@@ -91,11 +98,10 @@ class OpenexchangeratesData(object):
     """Get data from Openexchangerates.org."""
 
     # pylint: disable=too-many-arguments
-    def __init__(self, resource, api_key, base, quote, data):
+    def __init__(self, resource, parameters, quote):
         """Initialize the data object."""
         self._resource = resource
-        self._api_key = api_key
-        self._base = base
+        self._parameters = parameters
         self._quote = quote
         self.data = None
 
@@ -103,12 +109,10 @@ class OpenexchangeratesData(object):
     def update(self):
         """Get the latest data from openexchangerates.org."""
         try:
-            result = requests.get(self._resource, params={'base': self._base,
-                                                          'app_id':
-                                                          self._api_key},
-                                  timeout=10)
+            result = requests.get(
+                self._resource, params=self._parameters, timeout=10)
             self.data = result.json()['rates']
         except requests.exceptions.HTTPError:
-            _LOGGER.error("Check the Openexchangerates API Key")
+            _LOGGER.error("Check the Openexchangerates API key")
             self.data = None
             return False
diff --git a/homeassistant/const.py b/homeassistant/const.py
index 56712b9a04d..69c340db3db 100644
--- a/homeassistant/const.py
+++ b/homeassistant/const.py
@@ -58,6 +58,7 @@ CONF_AFTER = 'after'
 CONF_ALIAS = 'alias'
 CONF_API_KEY = 'api_key'
 CONF_AUTHENTICATION = 'authentication'
+CONF_BASE = 'base'
 CONF_BEFORE = 'before'
 CONF_BELOW = 'below'
 CONF_BLACKLIST = 'blacklist'
@@ -113,6 +114,7 @@ CONF_PIN = 'pin'
 CONF_PLATFORM = 'platform'
 CONF_PORT = 'port'
 CONF_PREFIX = 'prefix'
+CONF_QUOTE = 'quote'
 CONF_RECIPIENT = 'recipient'
 CONF_RESOURCE = 'resource'
 CONF_RESOURCES = 'resources'