@Gary **********
to get the first extension you must season the 800k for 2 months before applying then maintain the 800k for 3 months into the extension then never fall below 400k for the rest of the year. When getting a new extension the IO will check that these conditions were met for the first year. If, at any point, the balance in the account fell below these limits then the conditions were not met and the first extension will be void so you'd be back at square one and need a new Non-O to start again. If the conditions were met and, at the same time, there were 12 consecutive monthly international deposits of at least 65k then this can be used for the second extension (and the third etc. if continued).