This is the repeat of my earlier post but more straight forward and simplified to attract some hits. My 'Payments' section of payslip shows (example ofcourse

Total Gross Pay : 4000 GBP
Total Taxable Pay : 3780 GBP
This is because some part of my gross pay funds benefits, which are non-taxable (like pension, insurance etc.)
I am not able to find any clear guidelines in this respect on UKBA portal but most posts on this forum suggests only taxable salary can be used for earnings.
Can I use 'Total Gross Pay' or it could only be 'Total Taxable Pay'?
Many thanks,
nks