as from my experience..we applied our son for british citizenship last november 2008. We submitted our marriage certificate my baby's birth certificate, my birth certificate, (all NSO copy) hubbys long copy of birth certificate our passport and hospitals bills and pre natal check up...like ultrasounds etc. We pay certain fees for registration and for hard copy of british style birth certificate. When we sumbit those papers they told us that there maybe an interview after 10 days. So we waited. 10 days passed but no calls from embassy. Then 6 weeks after we recieved a call from them saying that my babys paper is ok and that his birth certificate is ready to be collected. We're happy...my baby is now a brit. As for applying for passport. You may apply for passport at the same time you apply for his citizenship or you can do one at a time. If registred first and wants to apply for passport all you have to submit to them is his british style certificate and you can get your childs passport for 10 days. Hope this help...and good luck