Problem with postal code/zip code IMM5669 question 12

[vahidmed]

Unfortunately I have changed my address a lot in past 10 years and I can’t remember none of my flats postal code except my current flat!!!
Can I use N/A or don’t remember in the postal code field in IMM5669 question 12?
If the answer is NO :'(
Please help me how can I fill this fields, because it’s impossible to achieve postal code of for example my GARRISON DORMITORY!!!
Thanks ;D

 

[omarko]

dont worry the rest use the current .......current is important...goodluck