Where RTI submissions remain outstanding, by default the number outstanding will be brought to your attention on your RTI menu header:

The BrightPay starting screen will also indicate this, where this column has been selected:

Should you wish to exclude an RTI submission from your 'unsent submission count', within the RTI utility, simply select the submission from the left hand listing, followed by More > Exclude from 'Unsent Submissions' Count:

 

This will in turn remove/decrease the number of submissions outstanding from your RTI menu header, as well as from your starting screen (where applicable).