00 isn't part of the country code, it is a commonly used international access prefix.
353 is the country code for the Republic of Ireland.
5 is the first digit of the Irish landline area code, somewhere in the central or southeastern part of the country. You need 1 or 2 more digits to be more specific.
Luton's dialling code is 01582.
567218 is not a dialling code from the UK, which all start with zero. The dialling code for Glasgow, Scotland is 0141.
The international dialling code for mainline China is +86
0141 is Glasgow's dialling code. 952 is not a dialling code in any part of the UK.
The country code for Poland is +48, and Kraków is city code 12. From the UK, dial 00 48 12.
The dialling code from UK to Australia is 00 61.
+51
001
Portugal
The international dialling code for Germany is 49 So, if phoning from the UK, dial 0049
Dialling code for Switzerland is +41
In the UK, 01709 is the area code for Rotherham.