Hi Ugur,  you can call Home Office lost pass letters office 03001232253 and ask them ,what to do. It is on gov.uk website .Info about this subject  www.gov.uk/life-in-the-uk-test/what-happens-test

Or just simply Google " naturalisation. life in the uk lost'

bst rgds

Hello

Would  anyone advise whether there is a need to take the Life in the UK test to apply for citizenship  as I have lost the Original Certificate .

Thank you

Ugur

Did you submit Life in the UK test when you applied for ILR?

regards