diff --git a/stdnum/ph/__init__.py b/stdnum/ph/__init__.py
new file mode 100644
index 00000000..f5dee782
--- /dev/null
+++ b/stdnum/ph/__init__.py
@@ -0,0 +1,24 @@
+# __init__.py - collection of Philippines numbers
+# coding: utf-8
+#
+# Copyright (C) 2023 Leandro Regueiro
+#
+# 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
+
+"""Collection of Philippines numbers."""
+
+# provide aliases
+from stdnum.ph import tin as vat  # noqa: F401
diff --git a/stdnum/ph/tin.py b/stdnum/ph/tin.py
new file mode 100644
index 00000000..c967a2dc
--- /dev/null
+++ b/stdnum/ph/tin.py
@@ -0,0 +1,114 @@
+# tin.py - functions for handling Philippines TIN numbers
+# coding: utf-8
+#
+# Copyright (C) 2023 Leandro Regueiro
+#
+# 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
+
+"""TIN (Taxpayer Identification Number, Philippines tax number).
+
+This number consists of 9 digits (for individual taxpayers), or 12 digits (for
+bussinesses). A thirteenth digit will be added in the future for businesses).
+It is usually separated using hyphens to make it easier to read, like
+XXX-XXX-XXX-XXX.
+
+The first digit identifies the type of taxpayer: 0 for businesses and 1 to 9
+for individual taxpayers. The following seven digits are a sequence. The ninth
+digit is the check digit.
+
+The last three digits (four in the future), for businesses only, correspond to
+the branch code. If the branch code is not specified, then it defaults to 000.
+
+It is not specified in the official documents, but it is not uncommon that some
+letters are appended to the businesses TIN to tell whether it is subject to
+VAT, usually N to say it is not subject and V to tell that it is.
+
+More information:
+
+* https://www.ntrc.gov.ph/images/journal/j20141112a.pdf
+* https://wiki.scn.sap.com/wiki/display/CRM/Philippines
+* https://help.sap.com/doc/saphelp_erp2005/6.0/ja-JP/d8/663e399265df0ee10000000a11402f/content.htm
+* https://world.salestaxhandbook.com/ph-philippines
+
+>>> validate('239-072-842')
+'239072842'
+>>> validate('239-072-842-000')
+'239072842000'
+>>> validate('12345')
+Traceback (most recent call last):
+    ...
+InvalidLength: ...
+>>> validate('12345678X')
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+>>> format('239072842000')
+'239-072-842-000'
+"""  # noqa: E501
+
+from stdnum.exceptions import *
+from stdnum.util import clean, isdigits
+
+
+def compact(number):
+    """Convert the number to the minimal representation.
+
+    This strips the number of any valid separators and removes surrounding
+    whitespace.
+    """
+    number = clean(number, ' -').upper().strip()
+    # Normalize unofficial code telling whether it is subject or not to VAT.
+    number = number.replace('NONVAT', 'N')
+    number = number.replace('NVAT', 'N')
+    number = number.replace('NV', 'N')
+    number = number.replace('VAT', 'V')
+    # Append the default branch code for business TIN numbers having unofficial
+    # VAT letter.
+    if len(number) == 10 and number[-1] in ('N', 'V'):
+        number = number[:-1] + '000' + number[-1]
+    return number
+
+
+def validate(number):
+    """Check if the number is a valid Philippines TIN number.
+
+    This checks the length and formatting.
+    """
+    number = compact(number)
+    if len(number) not in (9, 12, 13, 14):
+        raise InvalidLength()
+    has_wrong_format = not (isdigits(number) or
+                            (number[-1] in ('N', 'V') and
+                             isdigits(number[:-1])))
+    if has_wrong_format:
+        raise InvalidFormat()
+    return number
+
+
+def is_valid(number):
+    """Check if the number is a valid Philippines TIN number."""
+    try:
+        return bool(validate(number))
+    except ValidationError:
+        return False
+
+
+def format(number):
+    """Reformat the number to the standard presentation format."""
+    number = compact(number)
+    if len(number) < 12:
+        return '-'.join([number[:3], number[3:6], number[6:]])
+    return '-'.join([number[:3], number[3:6], number[6:9], number[9:]])
diff --git a/tests/test_ph_tin.doctest b/tests/test_ph_tin.doctest
new file mode 100644
index 00000000..b694bf82
--- /dev/null
+++ b/tests/test_ph_tin.doctest
@@ -0,0 +1,364 @@
+test_ph_tin.doctest - more detailed doctests for stdnum.ph.tin module
+
+Copyright (C) 2023 Leandro Regueiro
+
+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
+
+
+This file contains more detailed doctests for the stdnum.ph.tin module. It
+tries to test more corner cases and detailed functionality that is not really
+useful as module documentation.
+
+>>> from stdnum.ph import tin
+
+
+Tests for some corner cases.
+
+>>> tin.validate('239-072-842')
+'239072842'
+>>> tin.validate('239-072-842V')
+'239072842000V'
+>>> tin.validate('239-072-842-000')
+'239072842000'
+>>> tin.validate('239-072-842-000N')
+'239072842000N'
+>>> tin.validate('239-072-842-0000')
+'2390728420000'
+>>> tin.validate('239-072-842-0000V')
+'2390728420000V'
+>>> tin.validate('12345')
+Traceback (most recent call last):
+    ...
+InvalidLength: ...
+>>> tin.validate('12345678X')
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+>>> tin.validate('X23456789')
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+>>> tin.validate('X23456789V')
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+>>> tin.format('239072842')
+'239-072-842'
+>>> tin.format('239072842V')
+'239-072-842-000V'
+>>> tin.format('239072842000')
+'239-072-842-000'
+>>> tin.format('2390728420000')
+'239-072-842-0000'
+
+
+These have been found online and should all be valid numbers.
+
+>>> numbers = '''
+...
+... 005-011-362-000
+... 000-050-036-008
+... 000-050-043-012
+... 000-111-016-000
+... 000-143-093
+... 000-145-715-000
+... 000-171-929-000
+... 000-177-334-000 Non-VAT
+... 000-329-993-000
+... 000-333-948-000
+... 000-348-276
+... 000-360-191-000
+... 000-360-191-011
+... 000-384-446-000
+... 000-400-353-000
+... 000-413-851-000
+... 000-474-804-000
+... 000-502-501
+... 001-609-075-000
+... 001-707-269-000
+... 002-286-250-000
+... 003-508-768-000
+... 003-509-124-000
+... 004-589-684-003
+... 004-591-735-000 VAT
+... 004-622-551-000
+... 004-780-008-005
+... 004-840-797
+... 004-845-988-000
+... 005-249-453-014
+... 052-104-040-767
+... 100-192-890
+... 100-200-013-000
+... 100-200-909-000
+... 100-455-411-000
+... 103-768-233
+... 104-035-802-000
+... 146-475-945
+... 162-880-637-000
+... 175-130-354-000
+... 177-438-716-000
+... 193-599-790
+... 200-671-974-000
+... 200-937-884-006
+... 222-175-867-001
+... 223-376-875-000
+... 223-518-336-000 Non-VAT
+... 224-527-159-000
+... 230-338-434-000
+... 232-702-168-000
+... 239-072-842
+... 254-577-685-000
+... 320-157-356-094
+... 340-003-498-120 VAT
+... 348-717-000
+... 109-102-132 NV
+... 124-951-682 NV
+... 004-754-985 VAT
+... 890-135-517-438NV
+... 182-843-767 NV
+... 000-073-706 vat
+... 000-310-215-020 Vat
+... 935-112-421NV
+... 005-160-067 VAT
+... 005-881-689 VAT
+... 005-168-597 VAT
+... 005-988-752 VAT
+... 926-792-477 NV
+... 103-989-095-000-VAT
+... 922-917-654 NV
+... 005-159-765 VAT
+... 005-168-902 Vat
+... 115-707-189 vat
+... 002-332-000-013 VAT
+... 103-915-682-VAT
+... 005-161-557 vat
+... 000-081-553-028 Vat
+... 100-079-484 VAT
+... 100-080-002 VAT
+... 129-202-158 vat
+... 000-074-274 vat
+... 132-371-491 Vat
+... 004-749-477 NV
+... 000-076-775 vat
+... 148-016-939 Vat
+... 000-075-040V
+... 004-751-415 VAT
+... 000-264-680 VAT
+... 127-471-217 NVAT
+... 005-162-365 VAT
+... 890-003-375-571 VAT
+... 100-082-501 Vat
+... 890-100-078-619 VAT
+... 113-000-074-274 Vat
+... 000-844-851-000-VAT
+... 113-000-264-828 vat
+... 132-369-800 VAT
+... 003-375-397 VAT
+... 131-840-857 NV
+... 000-050-043-014 VAT
+... 000-075-476 Vat
+... 100-080-156 VAT
+... 000-330-890-000 vat
+... 005-162-036 NV
+... 001-648-111-004 VAT
+... 900-757-474 NV
+... 936-888-467NV
+... 004-475-204-002 VAT
+... 890-000-074-144 VAT
+... 900-754-474NV
+... 123-998-322 vat
+... 152-325-282 Vat
+... 004-326-444-VAT
+... 000-331-997-001 VAT
+... 175-494-492 NVAT
+... 906-750-006-000 NV
+... 000-163-731-001 vat
+... 000-066-016-002 Vat
+... 890-122-433-129 Vat
+... 932-699-595 NV
+... 100-082-182 Vat
+... 101-171-867VAT
+... 000-075-354 Vat
+... 000-075-589-VAT
+... 005-161-741VAT
+... 100-079-033 Vat
+... 202-845-266-000 Vat
+... 179-386-284 VAT
+... 163-800-132 NV
+... 000-069-873-005 vat
+... 108-683-346 Vat
+... 141-841-341 VAT
+... 118-437-177 NV
+... 222-837-340-000 VAT
+... 100-078-928 VAT
+... 000-076-380 VAT
+... 123-980-652VAT
+... 174-602-454 VAT
+... 189-801-842V
+... 005-814-108 Vat
+... 905-082-345-000 VAT
+... 000-169-318-024 vat
+... 890-100-080-867 Vat
+... 923-717-148 vat
+... 124-957-408 VAT
+... 189-770-986 VAT
+... 148-847-257 NV
+... 920-521-606 NV
+... 105-307-083 NV
+... 001-006-503 VAT
+... 146-200-558-000 Vat
+... 946-940-013 Vat
+... 006-843-862 Vat
+... 181-715-165 NV
+... 181-721-741 Vat
+... 003-876-506VAT
+... 101-611-294-000Vat
+... 160-903-052 VAT
+... 000-172-881-002 vat
+... 000-171-929-015 VAT
+... 148-032-938 NV
+... 913-887-131 vat
+... 002-645-341VAT
+... 000-077-154 VAT
+... 002-623-291 VAT
+... 158-022-176 VAT
+... 005-170-769 VAT
+... 100-084-030 VAT
+... 271-275-226-001 NV
+... 925-885-337 NV
+... 000-132-948-002 Vat
+... 005-160-816 VAT
+... 295-211-531-000 vat
+... 190-480-131 VAT
+... 000-076-516 VAT
+... 006-595-182
+... 004-774-849
+... 230-222-975
+... 000-527-434
+... 005-378-235
+... 000-528-611
+... 002-829-391
+... 118-247-725
+... 000-604-041
+... 301-172-053
+... 007-993-450
+... 130-725-714
+... 008-744-348
+... 007-995-035
+... 005-591-328
+... 007-308-455
+... 007-993-442
+... 230-222-578
+... 000-391-438
+... 107-771-398
+... 101-563-982
+... 123-304-975
+... 113-423-143
+... 102-096-694
+... 102-081-718
+... 120-115-828
+... 217-197-087
+... 132-203-939
+... 111-805-104
+... 117-798-339
+... 117-798-397
+... 111-708-099
+... 117-798-388
+... 111-805-120
+... 108-750-432
+... 111-805-058
+... 156-609-278
+... 120-099-848
+... 120-960-387
+... 120-960-779
+... 101-550-602
+... 120-130-884
+... 265-857-209
+... 235-572-492
+... 000-463-069
+... 004-774-849
+... 000-137-755
+... 230-000-334-038
+... 235-572-492
+... 172958490
+... 102 650 969 000
+... 003-509-116-000
+... 004-460-118-000
+... 136-421-419
+... 203-742-960
+... 202-346-036-000
+... 948-159-869
+... 168-338-289
+... 183-803-717-001
+... 239-569-635
+... 008-222-233
+... 117-411-362
+... 925-868-738-000
+... 918-271-855-000
+... 275-374-483
+... 005-106-150
+... 146-199-843
+... 204-727-396
+... 246-188-725
+... 204-727-396
+... 116-636-114
+... 116-636-447
+... 221-215-023-000
+... 185-645-285
+... 108-935-298
+... 421187521
+... 454910793000
+... 170-172-592
+... 135-482-989
+... 111-161-025
+... 901-128-486-000
+... 126-623-464
+... 134-387-859
+... 922-427-587
+... 113-510-437
+... 937-467-730
+... 928-201-914
+... 734-680-373
+... 923-260-290
+... 115-895-948
+... 106-179-520
+... 225-659-044
+... 132-144-207
+... 132-946-740
+... 139-166-843
+... 131-282-586
+... 103-797-751
+... 115-783-383
+... 119-857-973
+... 115-957-357
+... 183-123-226
+... 103-561-688
+... 113-267-001
+... 000-916-384-000
+... 218-145-247
+... 111-784-903
+... 291-624-692
+... 120-669-246
+... 249-448-045
+... 268-492-045
+... 245-061-183
+... 153-780-713
+... 266-292-128
+... 401-934-883
+...
+... '''
+>>> [x for x in numbers.splitlines() if x and not tin.is_valid(x)]
+[]