Firstly ... congratulations on your success in the 'Life in the UK Test' -
no mean feat - considering its high pass mark of 75%!
Secondly ... 'Indefinite Leave to Remain' is simply an extension of the Spousal Visa - and/or (in
cases like
yours) FLR. Once
*ILR's attained, it means you're no longer subject to UK Immigration restrictions and can choose to live here permanently.
Similarly, *it's the penultimate step to applying for naturalisation ... otherwise known as British Citizenship. I see Joe has
ALREADY outlined the procedure - as well as the earliest [and the latest] qualifying dates pertaining to your eligibility for submission of the papers required which, as he mentions, may be done through the NCS ('National Checking Service') by prior arrangement with your nearest Local Authority.
Thirdly ... here's the
really good news:
Because of the timing of your forthcoming application, there'll be NO NEED for
you to take the Revised English Test(s) due to be introduced with effect from October.