How Do I Become A Full-Fledged Domain Registrar
Answer: To become a fully accredited ICANN registrar, you must complete a formal application process and submit a non-refundable $2,500 US application fee. The purpose of the application is to primarily understand your business and identify its capabilities e.g. the projected number of registrations per month, the management processes, maintenance capabilities of registrations, etc.
If you can provide all the supporting documents and answer all the application questions to reflect that you are qualified to be a full fledged registrar, after some follow up inquiries (and probably some more research) you will eventually receive notification that you qualify (or not).
At this point, you will need to sign an Accreditation Agreement with ICANN and Pay the Accreditation Fee. This yearly accreditation fee is roughly $4,000 US, in addition to some quarterly variable fees paid once you begin registering domains names which helps offset a portion of ICANN's operating costs. There is also a flat transaction-based gTLD fee of $0.25 charged for each new registration, renewal or transfer. All accredited registrars must have $70,000 in working capital to demonstrate that you have at least this much liquid capital.
Once you fill out all the necessary documents and pay all the associated fees, ICANN will notify the applicable registries of your accreditation and add you to the list of official registrars (these registry operators will then contact you to sign agreements and work out financial and technical details). The final step is to prepare customer agreements (which ICANN offers some guidance) including the Uniform Domain-Name Dispute Policy requirements which all accredited registrars are required to follow.
Next, enjoy your active status as a full-fledged domain registrar.