Hi sharmthasan,
I presume that you will be completing a paper Tax Return (SA105) as you are referring to Box 44.
If this is the case then you would enter the actual amount of any mortgage interest payments (only the interest element if there is also a capital element to the mortgage).
IE.You would enter a figure of £22723 in Box 44..
Please refer to the following link for further information:
UK property notes
Thank you.