Goldie. I would fail you straight off, before we even got to a job. I'm dead serious.
It is (and has been since long before your great-grandfather was born) a requirement of The Wiring Regulations that all works are inspected, tested and certified. If you haven't done this you haven't complied with the basic standard against which you will be judged. Having a third party issue a certificate hardly inspires confidence and, in any case, I doubt very much that your LABC is issuing BS 7671 Electrical Installation Certificates; Building Regulations Compliance Certificates, maybe, but they are not what you will be judged on.
The fact that you don't know this raises a huge question about your competence, as enshrined in Regulation 16 of the EAWR 1989.
Self-certification is a different thing altogether. Persons registered with a competent persons scheme are allowed to self-certify in retrospect that their work complies with the Building Regulations.
Sorry to pish on your chips, but your lack of understanding would be enough, for my part to fail you outright. If you do not have at least the EICs for the inspection then against what is your assessor going to compare your results during the assessment? You ain't ready mate... far from it.