CF99 tops the ranking, with 1 postcodes, ahead of TR23 and PA62. The full ranking is below, each entry linked to its page.

# District Post town Postcodes
1 CF99 Cardiff 1
2 TR23 Isles of Scilly 1
3 PA62 Isle of Mull 1
4 BN95 — 1
5 SO25 Winchester 1
6 BB94 Barnoldswick 1
7 BN91 Worthing 1
8 DH97 Durham 1
9 BS98 Bristol 1
10 PH42 Isle of Eigg 1
11 PH30 Corrour 1
12 DE99 Derby 1
13 PA63 Isle of Mull 1
14 GIR Bootle 1
15 PA74 Isle of Mull 1
16 L80 Bootle 1
17 TR22 Isles of Scilly 1
18 CH88 Chester 1
19 PH44 Isle of Canna 1
20 PH43 Isle of Rum 1
21 L68 Liverpool 1
22 L67 Liverpool 2
23 IV48 Isle of Skye 2
24 EH99 Edinburgh 2
25 DH98 Durham 2
26 G79 Glasgow 2
27 CW98 Crewe 2
28 PA64 Isle of Mull 2
29 G9 Glasgow 2
30 KW2 Lybster 2
31 CH30 Wirral 3
32 CH28 Wirral 3
33 PA25 Cairndow 3
34 DH99 Durham 3
35 KW13 Forsinard 3
36 LS98 Leeds 3
37 N81 London 3
38 AB99 Aberdeen 3
39 LE95 Leicester 3
40 PA68 Isle of Mull 3
41 LS99 Leeds 3
42 IV46 Isle of Skye 3
43 SS22 Southend-on-Sea 3
44 TR25 Isles of Scilly 3
45 WF90 Wakefield 3
46 PA71 Isle of Mull 4
47 NE85 Newcastle upon Tyne 4
48 PA69 Isle of Mull 4
49 BD97 Bingley 4
50 LE94 Leicester 4
51 CR44 Croydon 4
52 CA95 Workington 4
53 KW7 Berriedale 5
54 PH37 Glenfinnan 5
55 WR99 Worcester 5
56 PH38 Lochailort 5
57 IV99 Inverness 5
58 PA78 Isle of Coll 5
59 PA41 Isle of Gigha 5
60 KW11 Kinbrace 6

Source: Royal Mail postcode data. Compiled by Postcodes UK.

Frequently asked questions

Which UK postcode district has the fewest postcodes?

CF99 tops the list, with 1 postcodes, followed by TR23 and PA62.

How is this ranking measured?

This ranking is based on Royal Mail postcode data.