1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
# uen.py - functions for handling Singapore UEN numbers
# coding: utf-8
#
# Copyright (C) 2020 Leandro Regueiro
# Copyright (C) 2020 Arthur de Jong
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301 USA
"""UEN (Singapore's Unique Entity Number).
The Unique Entity Number (UEN) is a 9 or 10 digit identification issued by
the government of Singapore to businesses that operate with within Singapore.
Accounting and Corporate Regulatory Authority (ACRA)
There are three different formats:
* Business (ROB): It consists of 8 digits followed by a check letter.
* Local Company (ROC): It consists of 9 digits (the 4 leftmost digits
represent the year of issuance) followed by a check letter.
* Others: Consists of 10 characters, begins with either the R letter, or the
S letter or the T letter followed by 2 digits representing the last two
digits of the issuance year, followed by two letters representing the
entity type, 4 digits and finally a check letter.
More information:
* https://www.oecd.org/tax/automatic-exchange/crs-implementation-and-assistance/tax-identification-numbers/Singapore-TIN.pdf
* https://www.uen.gov.sg/ueninternet/faces/pages/admin/aboutUEN.jspx
>>> validate('00192200M')
'00192200M'
>>> validate('197401143C')
'197401143C'
>>> validate('S16FC0121D')
'S16FC0121D'
>>> validate('T01FC6132D')
'T01FC6132D'
>>> validate('123456')
Traceback (most recent call last):
...
InvalidLength: ...
"""
# There are some references to special 10-digit (or 7-digit) numbers that
# start with an F for foreign companies but it is unclear whether this is
# still current and not even examples of these numbers could be found.
from datetime import datetime
from stdnum.exceptions import *
from stdnum.util import clean, isdigits
OTHER_UEN_ENTITY_TYPES = (
'CC', 'CD', 'CH', 'CL', 'CM', 'CP', 'CS', 'CX', 'DP', 'FB', 'FC', 'FM',
'FN', 'GA', 'GB', 'GS', 'HS', 'LL', 'LP', 'MB', 'MC', 'MD', 'MH', 'MM',
'MQ', 'NB', 'NR', 'PA', 'PB', 'PF', 'RF', 'RP', 'SM', 'SS', 'TC', 'TU',
'VH', 'XL',
)
def compact(number):
"""Convert the number to the minimal representation.
This converts to uppercase and removes surrounding whitespace. It
also replaces the whitespace in UEN for foreign companies with
zeroes.
"""
return clean(number).upper().strip()
def calc_business_check_digit(number):
"""Calculate the check digit for the Business (ROB) number."""
number = compact(number)
weights = (10, 4, 9, 3, 8, 2, 7, 1)
return 'XMKECAWLJDB'[sum(int(n) * w for n, w in zip(number, weights)) % 11]
def _validate_business(number):
"""Perform validation on UEN - Business (ROB) numbers."""
if not isdigits(number[:-1]):
raise InvalidFormat()
if not number[-1].isalpha():
raise InvalidFormat()
if number[-1] != calc_business_check_digit(number):
raise InvalidChecksum()
return number
def calc_local_company_check_digit(number):
"""Calculate the check digit for the Local Company (ROC) number."""
number = compact(number)
weights = (10, 8, 6, 4, 9, 7, 5, 3, 1)
return 'ZKCMDNERGWH'[sum(int(n) * w for n, w in zip(number, weights)) % 11]
def _validate_local_company(number):
"""Perform validation on UEN - Local Company (ROC) numbers."""
if not isdigits(number[:-1]):
raise InvalidFormat()
current_year = str(datetime.now().year)
if number[:4] > current_year:
raise InvalidComponent()
if number[-1] != calc_local_company_check_digit(number):
raise InvalidChecksum()
return number
def calc_other_check_digit(number):
"""Calculate the check digit for the other entities number."""
number = compact(number)
alphabet = 'ABCDEFGHJKLMNPQRSTUVWX0123456789'
weights = (4, 3, 5, 3, 10, 2, 2, 5, 7)
return alphabet[(sum(alphabet.index(n) * w for n, w in zip(number, weights)) - 5) % 11]
def _validate_other(number):
"""Perform validation on other UEN numbers."""
if number[0] not in ('R', 'S', 'T'):
raise InvalidComponent()
if not isdigits(number[1:3]):
raise InvalidFormat()
current_year = str(datetime.now().year)
if number[0] == 'T' and number[1:3] > current_year[2:]:
raise InvalidComponent()
if number[3:5] not in OTHER_UEN_ENTITY_TYPES:
raise InvalidComponent()
if not isdigits(number[5:-1]):
raise InvalidFormat()
if number[-1] != calc_other_check_digit(number):
raise InvalidChecksum()
return number
def validate(number):
"""Check if the number is a valid Singapore UEN number."""
number = compact(number)
if len(number) not in (9, 10):
raise InvalidLength()
if len(number) == 9:
return _validate_business(number)
if isdigits(number[0]):
return _validate_local_company(number)
return _validate_other(number)
def is_valid(number):
"""Check if the number is a valid Singapore UEN number."""
try:
return bool(validate(number))
except ValidationError:
return False
def format(number):
"""Reformat the number to the standard presentation format."""
return compact(number)
|