IBAN formats allowing only numeric BBAN

From annawiki

As of 2012-08-10

Countries having numeric-only formats after the country code

Some countries have numeric-only BBAN formats. The one with the highest frequency is the 20n format, being used by five countries.

Countries using formats that are only numeric after the country code and the check characters are:

BBAN length ISO 3166-1 alpha-2 codes for countries Quantity of countries using that format Length is a multiple of 4
11 NO 1 no
12 BE 1 yes
14 FO, GL, FI (including AX), DK 4 no
15 SI 1 no
16 BS, AT, EE, LT 4 yes
17 HR, CR 2 no
18 DE, ME, RS 3 no
19 AE, IL 2 no
20 CZ, SK, ES, SE, TN 5 yes
21 PT 1 no
22 IS 1 no
23 MR 1 no
24 HU, PL 2 yes
11-24 28 12