No last or surname in passport

[REEZ]

Hi I have questions, if I don’t have last name in passport, only have given name, how do I write that in citizenship application?
I forgot how I wrote when applying for permanent resident, but I think I just put given name in that application and left last name blank, can I call immigration now and check this?
I also noticed IRD has possibly split my name into first and last name, which doesn’t match with passport, but not sure, do these things matter when applying citizenship?
It’s confusing as some forms we can’t leave last name blank.
Thanks

[Kelerei]

The best thing to do, in my opinion, is to contact the Citizenship Office to ask.

Note that you may need to fill out the paper form if the online application cannot handle the lack of a last name, and your application may be one of the lengthier ones in terms of processing time as data matching may be an issue (IRD would be one example).

[REEZ]

Thanks for replying, but how come immigration never had issue with that, as I am sure I left last name blank. Can I ask IRD to change the format of my name? Any ways I will check with immigration what they have in system.
I haven’t filled citizenship application online yet, but just wanted to know if there is an issue with leaving last name blank, I read some posts people have filled out their given name in last name and left first name blank.

[REEZ]

Update- I spoke to IRD about this they said it just shows as one name only when they print out any letters for citizenship so it’s not a problem if it’s written as first and last name in their system, but they can change it for me if I provide them the copy of passport.