First of all, telephone country codes never begin with zero.
If we take that number as +20 30, that would be country code +20 (Egypt), but the next two digits pose a problem. Egyptian area code 03 (which is to say +20 3) is Alexandria, but local numbers cannot begin with zero.
Conclusion: invalid international code
There are many countries that have domestic numbers beginning with 02030. For example, in the UK, 020 is London. In the Netherlands, 020 is Amsterdam.
That code belongs to a number in the Greater London area.
There is no UK telephone area code 02030. Area code 020 is London, and some numbers begin with 020 30, but the '30' is the beginning of the local number, not part of the area code.
The main number for reaching a telephone operator in the UK is 100.
A UK telephone number beginning with 074 is a mobile phone.
It is a mobile telephone number for the UK.
Call the customer service department of your telephone company.
A UK telephone number beginning with +44 754 is a mobile.
That's a UK number - HOWEVER - numbers starting with 06 in the UK are not in use yet.
This is a mobile (cell) phone number so could be anywhere in the UK.
There will be a large number of Eileen Walton's living in the UK, therefore you will need to narrow the search down
UK -- 01536 396366
01792 is the area code for Swansea
+ 44 1372 360255
118118