diff --git a/uncloud/__init__.py b/uncloud/__init__.py
index 9e2545a..e69de29 100644
--- a/uncloud/__init__.py
+++ b/uncloud/__init__.py
@@ -1,4 +0,0 @@
-# Define DecimalField properties, used to represent amounts of money.
-# Used in pay and auth
-AMOUNT_MAX_DIGITS=10
-AMOUNT_DECIMALS=2
diff --git a/uncloud_auth/models.py b/uncloud_auth/models.py
index c3a0912..4549a2a 100644
--- a/uncloud_auth/models.py
+++ b/uncloud_auth/models.py
@@ -2,7 +2,7 @@ from django.contrib.auth.models import AbstractUser
 from django.db import models
 from django.core.validators import MinValueValidator
 
-from uncloud import AMOUNT_DECIMALS, AMOUNT_MAX_DIGITS
+from uncloud_pay import AMOUNT_DECIMALS, AMOUNT_MAX_DIGITS
 
 from uncloud_pay.models import get_balance_for_user
 
diff --git a/uncloud_auth/serializers.py b/uncloud_auth/serializers.py
index 71aeb03..e01aab3 100644
--- a/uncloud_auth/serializers.py
+++ b/uncloud_auth/serializers.py
@@ -1,7 +1,7 @@
 from django.contrib.auth import get_user_model
 from rest_framework import serializers
 
-from uncloud import AMOUNT_DECIMALS, AMOUNT_MAX_DIGITS
+from uncloud_pay import AMOUNT_DECIMALS, AMOUNT_MAX_DIGITS
 
 class UserSerializer(serializers.ModelSerializer):
 
diff --git a/uncloud_pay/__init__.py b/uncloud_pay/__init__.py
index e69de29..0dd3b3f 100644
--- a/uncloud_pay/__init__.py
+++ b/uncloud_pay/__init__.py
@@ -0,0 +1,247 @@
+from django.utils.translation import gettext_lazy as _
+
+# Define DecimalField properties, used to represent amounts of money.
+AMOUNT_MAX_DIGITS=10
+AMOUNT_DECIMALS=2
+
+# http://xml.coverpages.org/country3166.html
+COUNTRIES = (
+    ('AD', _('Andorra')),
+    ('AE', _('United Arab Emirates')),
+    ('AF', _('Afghanistan')),
+    ('AG', _('Antigua & Barbuda')),
+    ('AI', _('Anguilla')),
+    ('AL', _('Albania')),
+    ('AM', _('Armenia')),
+    ('AN', _('Netherlands Antilles')),
+    ('AO', _('Angola')),
+    ('AQ', _('Antarctica')),
+    ('AR', _('Argentina')),
+    ('AS', _('American Samoa')),
+    ('AT', _('Austria')),
+    ('AU', _('Australia')),
+    ('AW', _('Aruba')),
+    ('AZ', _('Azerbaijan')),
+    ('BA', _('Bosnia and Herzegovina')),
+    ('BB', _('Barbados')),
+    ('BD', _('Bangladesh')),
+    ('BE', _('Belgium')),
+    ('BF', _('Burkina Faso')),
+    ('BG', _('Bulgaria')),
+    ('BH', _('Bahrain')),
+    ('BI', _('Burundi')),
+    ('BJ', _('Benin')),
+    ('BM', _('Bermuda')),
+    ('BN', _('Brunei Darussalam')),
+    ('BO', _('Bolivia')),
+    ('BR', _('Brazil')),
+    ('BS', _('Bahama')),
+    ('BT', _('Bhutan')),
+    ('BV', _('Bouvet Island')),
+    ('BW', _('Botswana')),
+    ('BY', _('Belarus')),
+    ('BZ', _('Belize')),
+    ('CA', _('Canada')),
+    ('CC', _('Cocos (Keeling) Islands')),
+    ('CF', _('Central African Republic')),
+    ('CG', _('Congo')),
+    ('CH', _('Switzerland')),
+    ('CI', _('Ivory Coast')),
+    ('CK', _('Cook Iislands')),
+    ('CL', _('Chile')),
+    ('CM', _('Cameroon')),
+    ('CN', _('China')),
+    ('CO', _('Colombia')),
+    ('CR', _('Costa Rica')),
+    ('CU', _('Cuba')),
+    ('CV', _('Cape Verde')),
+    ('CX', _('Christmas Island')),
+    ('CY', _('Cyprus')),
+    ('CZ', _('Czech Republic')),
+    ('DE', _('Germany')),
+    ('DJ', _('Djibouti')),
+    ('DK', _('Denmark')),
+    ('DM', _('Dominica')),
+    ('DO', _('Dominican Republic')),
+    ('DZ', _('Algeria')),
+    ('EC', _('Ecuador')),
+    ('EE', _('Estonia')),
+    ('EG', _('Egypt')),
+    ('EH', _('Western Sahara')),
+    ('ER', _('Eritrea')),
+    ('ES', _('Spain')),
+    ('ET', _('Ethiopia')),
+    ('FI', _('Finland')),
+    ('FJ', _('Fiji')),
+    ('FK', _('Falkland Islands (Malvinas)')),
+    ('FM', _('Micronesia')),
+    ('FO', _('Faroe Islands')),
+    ('FR', _('France')),
+    ('FX', _('France, Metropolitan')),
+    ('GA', _('Gabon')),
+    ('GB', _('United Kingdom (Great Britain)')),
+    ('GD', _('Grenada')),
+    ('GE', _('Georgia')),
+    ('GF', _('French Guiana')),
+    ('GH', _('Ghana')),
+    ('GI', _('Gibraltar')),
+    ('GL', _('Greenland')),
+    ('GM', _('Gambia')),
+    ('GN', _('Guinea')),
+    ('GP', _('Guadeloupe')),
+    ('GQ', _('Equatorial Guinea')),
+    ('GR', _('Greece')),
+    ('GS', _('South Georgia and the South Sandwich Islands')),
+    ('GT', _('Guatemala')),
+    ('GU', _('Guam')),
+    ('GW', _('Guinea-Bissau')),
+    ('GY', _('Guyana')),
+    ('HK', _('Hong Kong')),
+    ('HM', _('Heard & McDonald Islands')),
+    ('HN', _('Honduras')),
+    ('HR', _('Croatia')),
+    ('HT', _('Haiti')),
+    ('HU', _('Hungary')),
+    ('ID', _('Indonesia')),
+    ('IE', _('Ireland')),
+    ('IL', _('Israel')),
+    ('IN', _('India')),
+    ('IO', _('British Indian Ocean Territory')),
+    ('IQ', _('Iraq')),
+    ('IR', _('Islamic Republic of Iran')),
+    ('IS', _('Iceland')),
+    ('IT', _('Italy')),
+    ('JM', _('Jamaica')),
+    ('JO', _('Jordan')),
+    ('JP', _('Japan')),
+    ('KE', _('Kenya')),
+    ('KG', _('Kyrgyzstan')),
+    ('KH', _('Cambodia')),
+    ('KI', _('Kiribati')),
+    ('KM', _('Comoros')),
+    ('KN', _('St. Kitts and Nevis')),
+    ('KP', _('Korea, Democratic People\'s Republic of')),
+    ('KR', _('Korea, Republic of')),
+    ('KW', _('Kuwait')),
+    ('KY', _('Cayman Islands')),
+    ('KZ', _('Kazakhstan')),
+    ('LA', _('Lao People\'s Democratic Republic')),
+    ('LB', _('Lebanon')),
+    ('LC', _('Saint Lucia')),
+    ('LI', _('Liechtenstein')),
+    ('LK', _('Sri Lanka')),
+    ('LR', _('Liberia')),
+    ('LS', _('Lesotho')),
+    ('LT', _('Lithuania')),
+    ('LU', _('Luxembourg')),
+    ('LV', _('Latvia')),
+    ('LY', _('Libyan Arab Jamahiriya')),
+    ('MA', _('Morocco')),
+    ('MC', _('Monaco')),
+    ('MD', _('Moldova, Republic of')),
+    ('MG', _('Madagascar')),
+    ('MH', _('Marshall Islands')),
+    ('ML', _('Mali')),
+    ('MN', _('Mongolia')),
+    ('MM', _('Myanmar')),
+    ('MO', _('Macau')),
+    ('MP', _('Northern Mariana Islands')),
+    ('MQ', _('Martinique')),
+    ('MR', _('Mauritania')),
+    ('MS', _('Monserrat')),
+    ('MT', _('Malta')),
+    ('MU', _('Mauritius')),
+    ('MV', _('Maldives')),
+    ('MW', _('Malawi')),
+    ('MX', _('Mexico')),
+    ('MY', _('Malaysia')),
+    ('MZ', _('Mozambique')),
+    ('NA', _('Namibia')),
+    ('NC', _('New Caledonia')),
+    ('NE', _('Niger')),
+    ('NF', _('Norfolk Island')),
+    ('NG', _('Nigeria')),
+    ('NI', _('Nicaragua')),
+    ('NL', _('Netherlands')),
+    ('NO', _('Norway')),
+    ('NP', _('Nepal')),
+    ('NR', _('Nauru')),
+    ('NU', _('Niue')),
+    ('NZ', _('New Zealand')),
+    ('OM', _('Oman')),
+    ('PA', _('Panama')),
+    ('PE', _('Peru')),
+    ('PF', _('French Polynesia')),
+    ('PG', _('Papua New Guinea')),
+    ('PH', _('Philippines')),
+    ('PK', _('Pakistan')),
+    ('PL', _('Poland')),
+    ('PM', _('St. Pierre & Miquelon')),
+    ('PN', _('Pitcairn')),
+    ('PR', _('Puerto Rico')),
+    ('PT', _('Portugal')),
+    ('PW', _('Palau')),
+    ('PY', _('Paraguay')),
+    ('QA', _('Qatar')),
+    ('RE', _('Reunion')),
+    ('RO', _('Romania')),
+    ('RU', _('Russian Federation')),
+    ('RW', _('Rwanda')),
+    ('SA', _('Saudi Arabia')),
+    ('SB', _('Solomon Islands')),
+    ('SC', _('Seychelles')),
+    ('SD', _('Sudan')),
+    ('SE', _('Sweden')),
+    ('SG', _('Singapore')),
+    ('SH', _('St. Helena')),
+    ('SI', _('Slovenia')),
+    ('SJ', _('Svalbard & Jan Mayen Islands')),
+    ('SK', _('Slovakia')),
+    ('SL', _('Sierra Leone')),
+    ('SM', _('San Marino')),
+    ('SN', _('Senegal')),
+    ('SO', _('Somalia')),
+    ('SR', _('Suriname')),
+    ('ST', _('Sao Tome & Principe')),
+    ('SV', _('El Salvador')),
+    ('SY', _('Syrian Arab Republic')),
+    ('SZ', _('Swaziland')),
+    ('TC', _('Turks & Caicos Islands')),
+    ('TD', _('Chad')),
+    ('TF', _('French Southern Territories')),
+    ('TG', _('Togo')),
+    ('TH', _('Thailand')),
+    ('TJ', _('Tajikistan')),
+    ('TK', _('Tokelau')),
+    ('TM', _('Turkmenistan')),
+    ('TN', _('Tunisia')),
+    ('TO', _('Tonga')),
+    ('TP', _('East Timor')),
+    ('TR', _('Turkey')),
+    ('TT', _('Trinidad & Tobago')),
+    ('TV', _('Tuvalu')),
+    ('TW', _('Taiwan, Province of China')),
+    ('TZ', _('Tanzania, United Republic of')),
+    ('UA', _('Ukraine')),
+    ('UG', _('Uganda')),
+    ('UM', _('United States Minor Outlying Islands')),
+    ('US', _('United States of America')),
+    ('UY', _('Uruguay')),
+    ('UZ', _('Uzbekistan')),
+    ('VA', _('Vatican City State (Holy See)')),
+    ('VC', _('St. Vincent & the Grenadines')),
+    ('VE', _('Venezuela')),
+    ('VG', _('British Virgin Islands')),
+    ('VI', _('United States Virgin Islands')),
+    ('VN', _('Viet Nam')),
+    ('VU', _('Vanuatu')),
+    ('WF', _('Wallis & Futuna Islands')),
+    ('WS', _('Samoa')),
+    ('YE', _('Yemen')),
+    ('YT', _('Mayotte')),
+    ('YU', _('Yugoslavia')),
+    ('ZA', _('South Africa')),
+    ('ZM', _('Zambia')),
+    ('ZR', _('Zaire')),
+    ('ZW', _('Zimbabwe')),
+)
diff --git a/uncloud_pay/models.py b/uncloud_pay/models.py
index c2b7378..bd73451 100644
--- a/uncloud_pay/models.py
+++ b/uncloud_pay/models.py
@@ -1,8 +1,8 @@
 from django.db import models
 from django.db.models import Q
 from django.contrib.auth import get_user_model
-from django.core.validators import MinValueValidator
 from django.utils.translation import gettext_lazy as _
+from django.core.validators import MinValueValidator
 from django.utils import timezone
 from django.core.exceptions import ObjectDoesNotExist, ValidationError
 
@@ -17,264 +17,15 @@ from decimal import Decimal
 
 import uncloud_pay.stripe
 from uncloud_pay.helpers import beginning_of_month, end_of_month
-from uncloud import AMOUNT_DECIMALS, AMOUNT_MAX_DIGITS
+from uncloud_pay import AMOUNT_DECIMALS, AMOUNT_MAX_DIGITS, COUNTRIES
 from uncloud.models import UncloudModel, UncloudStatus
 
 from decimal import Decimal
 import decimal
 
-# Define DecimalField properties, used to represent amounts of money.
-AMOUNT_MAX_DIGITS=10
-AMOUNT_DECIMALS=2
-
-# FIXME: check why we need +1 here.
-decimal.getcontext().prec = AMOUNT_DECIMALS + 1
-
 # Used to generate bill due dates.
 BILL_PAYMENT_DELAY=timedelta(days=10)
 
-# http://xml.coverpages.org/country3166.html
-COUNTRIES = (
-    ('AD', _('Andorra')),
-    ('AE', _('United Arab Emirates')),
-    ('AF', _('Afghanistan')),
-    ('AG', _('Antigua & Barbuda')),
-    ('AI', _('Anguilla')),
-    ('AL', _('Albania')),
-    ('AM', _('Armenia')),
-    ('AN', _('Netherlands Antilles')),
-    ('AO', _('Angola')),
-    ('AQ', _('Antarctica')),
-    ('AR', _('Argentina')),
-    ('AS', _('American Samoa')),
-    ('AT', _('Austria')),
-    ('AU', _('Australia')),
-    ('AW', _('Aruba')),
-    ('AZ', _('Azerbaijan')),
-    ('BA', _('Bosnia and Herzegovina')),
-    ('BB', _('Barbados')),
-    ('BD', _('Bangladesh')),
-    ('BE', _('Belgium')),
-    ('BF', _('Burkina Faso')),
-    ('BG', _('Bulgaria')),
-    ('BH', _('Bahrain')),
-    ('BI', _('Burundi')),
-    ('BJ', _('Benin')),
-    ('BM', _('Bermuda')),
-    ('BN', _('Brunei Darussalam')),
-    ('BO', _('Bolivia')),
-    ('BR', _('Brazil')),
-    ('BS', _('Bahama')),
-    ('BT', _('Bhutan')),
-    ('BV', _('Bouvet Island')),
-    ('BW', _('Botswana')),
-    ('BY', _('Belarus')),
-    ('BZ', _('Belize')),
-    ('CA', _('Canada')),
-    ('CC', _('Cocos (Keeling) Islands')),
-    ('CF', _('Central African Republic')),
-    ('CG', _('Congo')),
-    ('CH', _('Switzerland')),
-    ('CI', _('Ivory Coast')),
-    ('CK', _('Cook Iislands')),
-    ('CL', _('Chile')),
-    ('CM', _('Cameroon')),
-    ('CN', _('China')),
-    ('CO', _('Colombia')),
-    ('CR', _('Costa Rica')),
-    ('CU', _('Cuba')),
-    ('CV', _('Cape Verde')),
-    ('CX', _('Christmas Island')),
-    ('CY', _('Cyprus')),
-    ('CZ', _('Czech Republic')),
-    ('DE', _('Germany')),
-    ('DJ', _('Djibouti')),
-    ('DK', _('Denmark')),
-    ('DM', _('Dominica')),
-    ('DO', _('Dominican Republic')),
-    ('DZ', _('Algeria')),
-    ('EC', _('Ecuador')),
-    ('EE', _('Estonia')),
-    ('EG', _('Egypt')),
-    ('EH', _('Western Sahara')),
-    ('ER', _('Eritrea')),
-    ('ES', _('Spain')),
-    ('ET', _('Ethiopia')),
-    ('FI', _('Finland')),
-    ('FJ', _('Fiji')),
-    ('FK', _('Falkland Islands (Malvinas)')),
-    ('FM', _('Micronesia')),
-    ('FO', _('Faroe Islands')),
-    ('FR', _('France')),
-    ('FX', _('France, Metropolitan')),
-    ('GA', _('Gabon')),
-    ('GB', _('United Kingdom (Great Britain)')),
-    ('GD', _('Grenada')),
-    ('GE', _('Georgia')),
-    ('GF', _('French Guiana')),
-    ('GH', _('Ghana')),
-    ('GI', _('Gibraltar')),
-    ('GL', _('Greenland')),
-    ('GM', _('Gambia')),
-    ('GN', _('Guinea')),
-    ('GP', _('Guadeloupe')),
-    ('GQ', _('Equatorial Guinea')),
-    ('GR', _('Greece')),
-    ('GS', _('South Georgia and the South Sandwich Islands')),
-    ('GT', _('Guatemala')),
-    ('GU', _('Guam')),
-    ('GW', _('Guinea-Bissau')),
-    ('GY', _('Guyana')),
-    ('HK', _('Hong Kong')),
-    ('HM', _('Heard & McDonald Islands')),
-    ('HN', _('Honduras')),
-    ('HR', _('Croatia')),
-    ('HT', _('Haiti')),
-    ('HU', _('Hungary')),
-    ('ID', _('Indonesia')),
-    ('IE', _('Ireland')),
-    ('IL', _('Israel')),
-    ('IN', _('India')),
-    ('IO', _('British Indian Ocean Territory')),
-    ('IQ', _('Iraq')),
-    ('IR', _('Islamic Republic of Iran')),
-    ('IS', _('Iceland')),
-    ('IT', _('Italy')),
-    ('JM', _('Jamaica')),
-    ('JO', _('Jordan')),
-    ('JP', _('Japan')),
-    ('KE', _('Kenya')),
-    ('KG', _('Kyrgyzstan')),
-    ('KH', _('Cambodia')),
-    ('KI', _('Kiribati')),
-    ('KM', _('Comoros')),
-    ('KN', _('St. Kitts and Nevis')),
-    ('KP', _('Korea, Democratic People\'s Republic of')),
-    ('KR', _('Korea, Republic of')),
-    ('KW', _('Kuwait')),
-    ('KY', _('Cayman Islands')),
-    ('KZ', _('Kazakhstan')),
-    ('LA', _('Lao People\'s Democratic Republic')),
-    ('LB', _('Lebanon')),
-    ('LC', _('Saint Lucia')),
-    ('LI', _('Liechtenstein')),
-    ('LK', _('Sri Lanka')),
-    ('LR', _('Liberia')),
-    ('LS', _('Lesotho')),
-    ('LT', _('Lithuania')),
-    ('LU', _('Luxembourg')),
-    ('LV', _('Latvia')),
-    ('LY', _('Libyan Arab Jamahiriya')),
-    ('MA', _('Morocco')),
-    ('MC', _('Monaco')),
-    ('MD', _('Moldova, Republic of')),
-    ('MG', _('Madagascar')),
-    ('MH', _('Marshall Islands')),
-    ('ML', _('Mali')),
-    ('MN', _('Mongolia')),
-    ('MM', _('Myanmar')),
-    ('MO', _('Macau')),
-    ('MP', _('Northern Mariana Islands')),
-    ('MQ', _('Martinique')),
-    ('MR', _('Mauritania')),
-    ('MS', _('Monserrat')),
-    ('MT', _('Malta')),
-    ('MU', _('Mauritius')),
-    ('MV', _('Maldives')),
-    ('MW', _('Malawi')),
-    ('MX', _('Mexico')),
-    ('MY', _('Malaysia')),
-    ('MZ', _('Mozambique')),
-    ('NA', _('Namibia')),
-    ('NC', _('New Caledonia')),
-    ('NE', _('Niger')),
-    ('NF', _('Norfolk Island')),
-    ('NG', _('Nigeria')),
-    ('NI', _('Nicaragua')),
-    ('NL', _('Netherlands')),
-    ('NO', _('Norway')),
-    ('NP', _('Nepal')),
-    ('NR', _('Nauru')),
-    ('NU', _('Niue')),
-    ('NZ', _('New Zealand')),
-    ('OM', _('Oman')),
-    ('PA', _('Panama')),
-    ('PE', _('Peru')),
-    ('PF', _('French Polynesia')),
-    ('PG', _('Papua New Guinea')),
-    ('PH', _('Philippines')),
-    ('PK', _('Pakistan')),
-    ('PL', _('Poland')),
-    ('PM', _('St. Pierre & Miquelon')),
-    ('PN', _('Pitcairn')),
-    ('PR', _('Puerto Rico')),
-    ('PT', _('Portugal')),
-    ('PW', _('Palau')),
-    ('PY', _('Paraguay')),
-    ('QA', _('Qatar')),
-    ('RE', _('Reunion')),
-    ('RO', _('Romania')),
-    ('RU', _('Russian Federation')),
-    ('RW', _('Rwanda')),
-    ('SA', _('Saudi Arabia')),
-    ('SB', _('Solomon Islands')),
-    ('SC', _('Seychelles')),
-    ('SD', _('Sudan')),
-    ('SE', _('Sweden')),
-    ('SG', _('Singapore')),
-    ('SH', _('St. Helena')),
-    ('SI', _('Slovenia')),
-    ('SJ', _('Svalbard & Jan Mayen Islands')),
-    ('SK', _('Slovakia')),
-    ('SL', _('Sierra Leone')),
-    ('SM', _('San Marino')),
-    ('SN', _('Senegal')),
-    ('SO', _('Somalia')),
-    ('SR', _('Suriname')),
-    ('ST', _('Sao Tome & Principe')),
-    ('SV', _('El Salvador')),
-    ('SY', _('Syrian Arab Republic')),
-    ('SZ', _('Swaziland')),
-    ('TC', _('Turks & Caicos Islands')),
-    ('TD', _('Chad')),
-    ('TF', _('French Southern Territories')),
-    ('TG', _('Togo')),
-    ('TH', _('Thailand')),
-    ('TJ', _('Tajikistan')),
-    ('TK', _('Tokelau')),
-    ('TM', _('Turkmenistan')),
-    ('TN', _('Tunisia')),
-    ('TO', _('Tonga')),
-    ('TP', _('East Timor')),
-    ('TR', _('Turkey')),
-    ('TT', _('Trinidad & Tobago')),
-    ('TV', _('Tuvalu')),
-    ('TW', _('Taiwan, Province of China')),
-    ('TZ', _('Tanzania, United Republic of')),
-    ('UA', _('Ukraine')),
-    ('UG', _('Uganda')),
-    ('UM', _('United States Minor Outlying Islands')),
-    ('US', _('United States of America')),
-    ('UY', _('Uruguay')),
-    ('UZ', _('Uzbekistan')),
-    ('VA', _('Vatican City State (Holy See)')),
-    ('VC', _('St. Vincent & the Grenadines')),
-    ('VE', _('Venezuela')),
-    ('VG', _('British Virgin Islands')),
-    ('VI', _('United States Virgin Islands')),
-    ('VN', _('Viet Nam')),
-    ('VU', _('Vanuatu')),
-    ('WF', _('Wallis & Futuna Islands')),
-    ('WS', _('Samoa')),
-    ('YE', _('Yemen')),
-    ('YT', _('Mayotte')),
-    ('YU', _('Yugoslavia')),
-    ('ZA', _('South Africa')),
-    ('ZM', _('Zambia')),
-    ('ZR', _('Zaire')),
-    ('ZW', _('Zimbabwe')),
-)
-
 # Initialize logger.
 logger = logging.getLogger(__name__)