diff --git a/lib/al/dune b/lib/al/dune
new file mode 100644
index 0000000..90f5d36
--- /dev/null
+++ b/lib/al/dune
@@ -0,0 +1,4 @@
+(library
+ (name al)
+ (modules nipt)
+ (libraries tools))
diff --git a/lib/al/nipt.ml b/lib/al/nipt.ml
new file mode 100644
index 0000000..51480dd
--- /dev/null
+++ b/lib/al/nipt.ml
@@ -0,0 +1,28 @@
+open Tools
+
+exception Invalid_length
+exception Invalid_format
+
+let nipt_re = Str.regexp "^[A-M][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][A-Z]$"
+
+let compact number =
+  let number =
+    Utils.clean number " " |> String.uppercase_ascii |> String.trim
+  in
+  if String.starts_with number ~prefix:"AL" then
+    String.sub number 2 (String.length number - 2)
+  else if String.starts_with number ~prefix:"(AL)" then
+    String.sub number 4 (String.length number - 4)
+  else number
+
+let validate number =
+  let number = compact number in
+  print_string number;
+  if not (Str.string_match nipt_re number 0) then raise Invalid_format
+  else number
+
+let is_valid number =
+  try
+    ignore (validate number);
+    true
+  with _ -> false
diff --git a/lib/al/nipt.mli b/lib/al/nipt.mli
new file mode 100644
index 0000000..6e21a80
--- /dev/null
+++ b/lib/al/nipt.mli
@@ -0,0 +1,32 @@
+(*
+NIPT, NUIS (Numri i Identifikimit për Personin e Tatueshëm, Albanian tax number).
+
+The Albanian NIPT is a 10-digit number with the first and last character
+being letters. The number is assigned to individuals and organisations for
+tax purposes.
+
+The first letter indicates the decade the number was assigned or date birth
+date for individuals, followed by a digit for the year. The next two digits
+contain the month (and gender for individuals and region for organisations)
+followed by two digits for the day of the month. The remainder is a serial
+followed by a check letter (check digit algorithm unknown).   
+*)
+
+exception Invalid_length
+(** Exception raised when the NIPT number has an invalid length. *)
+
+exception Invalid_format
+(** Exception raised when the NIPT number has an invalid format. *)
+
+val nipt_re : Str.regexp
+
+val compact : string -> string
+(** [compact number] removes spaces and converts [number] to uppercase. *)
+
+val validate : string -> string
+(** [validate number] checks if [number] is a valid NIPT number.
+    It raises [Invalid_length] or [Invalid_format] if the number is not valid. *)
+
+val is_valid : string -> bool
+(** [is_valid number] checks if [number] is a valid NIPT number.
+    It returns [true] if the number is valid, [false] otherwise. *)
diff --git a/test/al/dune b/test/al/dune
new file mode 100644
index 0000000..77bd9c4
--- /dev/null
+++ b/test/al/dune
@@ -0,0 +1,4 @@
+(test
+ (name test_nipt)
+ (libraries alcotest al)
+ (modules test_nipt))
diff --git a/test/al/test_nipt.ml b/test/al/test_nipt.ml
new file mode 100644
index 0000000..af8d29d
--- /dev/null
+++ b/test/al/test_nipt.ml
@@ -0,0 +1,134 @@
+open Alcotest
+
+let test_is_valid () =
+  let numbers =
+    [
+      "J 98624806 P"
+    ; "J61827501H"
+    ; "J61922018S"
+    ; "J61923008Q"
+    ; "J62903770O"
+    ; "J66702410U"
+    ; "J67902218L"
+    ; "J67902618M"
+    ; "J73721043Q"
+    ; "J74517201G"
+    ; "J76418907K"
+    ; "J76705047U"
+    ; "J77411245Q"
+    ; "J78716317H"
+    ; "J82916489E"
+    ; "J86526614T"
+    ; "J91425005N"
+    ; "J93910409N"
+    ; "K 01725001F"
+    ; "K 11723003 M"
+    ; "K 37507987 N"
+    ; "K 41424801 U"
+    ; "K 47905861 R"
+    ; "K 63005203 O"
+    ; "K 67204202 P"
+    ; "K01730502W"
+    ; "K11515001T"
+    ; "K12113002H"
+    ; "K13001013H"
+    ; "K14019001H"
+    ; "K21622001M"
+    ; "K22218003V"
+    ; "K31518077S"
+    ; "K31525146H"
+    ; "K31526056N"
+    ; "K32203501H"
+    ; "K32801430W"
+    ; "K33714725W"
+    ; "K36308746I"
+    ; "K36520204A"
+    ; "K41315003J"
+    ; "K46621201I"
+    ; "K51518058O"
+    ; "K56417201G"
+    ; "K59418208E"
+    ; "K61617040L"
+    ; "K71822006R"
+    ; "K72113010E"
+    ; "K81428502L"
+    ; "K81618039O"
+    ; "K82418002C"
+    ; "K82612003J"
+    ; "K91725009J"
+    ; "K92402023O"
+    ; "L 22614402 H"
+    ; "L 62119008 A"
+    ; "L01622006F"
+    ; "L01717030C"
+    ; "L02023501H"
+    ; "L02226012N"
+    ; "L03321203G"
+    ; "L03929803I"
+    ; "L06426702Q"
+    ; "L07305201K"
+    ; "L08711201I"
+    ; "L11325024K"
+    ; "L11810502T"
+    ; "L12213005M"
+    ; "L14118803B"
+    ; "L21310054D"
+    ; "L21408015A"
+    ; "L21429502L"
+    ; "L21906001L"
+    ; "L21923507N"
+    ; "L22804207O"
+    ; "L24006002V"
+    ; "L29616001A"
+    ; "L31518001O"
+    ; "L32210507A"
+    ; "L32319014A"
+    ; "L32622601G"
+    ; "L41410025S"
+    ; "L41512005R"
+    ; "L42008005H"
+    ; "L42115015G"
+    ; "L42307007E"
+    ; "L44119601E"
+    ; "L47014204F"
+    ; "L48117101S"
+    ; "L52305009L"
+    ; "L58428303T"
+    ; "L62119008A"
+    ; "L72031013B"
+    ; "L81506043D"
+    ; "L81618040T"
+    ; "L82306024Q"
+    ; "L98602504L"
+    ; "M 02129023 S"
+    ; "M 11807013 N"
+    ; "M02129023 S"
+    ]
+  in
+  List.iter
+    (fun number -> check bool number true (Al.Nipt.is_valid number))
+    numbers
+
+let test_is_not_valid () =
+  let numbers =
+    [
+      "A 123 V"
+    ; "ABCDEF"
+    ; "1234567890"
+    ; "A B C D E F"
+    ; "J 986206 P"
+    ; "X 98624806 M"
+    ; "Z67902218L"
+    ]
+  in
+  List.iter
+    (fun number -> check bool number false (Al.Nipt.is_valid number))
+    numbers
+
+let suite =
+  [
+    ("test_validate", `Quick, test_is_valid)
+  ; ("test_is_not_valid", `Quick, test_is_not_valid)
+  ]
+
+let () = Alcotest.run "Us.Atin" [ ("suite", suite) ]