Question. What can I do if I am unable to get a copy of the requested birth (or marriage) certificate?
If a birth certificate is not available, generally one will be asked to submit a certificate of non-availability from the local authorities. Usually, additional evidence like a school-leaving certificate, doctor or midwife certificate, etc, is also required, along with sworn affidavits. Please note, however, that affidavits are not primary evidence and can be rejected unless an official in the foreign country explains why a birth certificate is not available.
 
Affidavits from people present at the birth usually may be used to show the details of a birth only after showing that a birth certificate has been destroyed, is unavailable, or was late issued. If the people writing the affidavits know that the birth was not reported to any civil or religious authority, they can state this in their affidavits.