wrting an address without postal code

as asked on the question, i have just sent a letter to my friend in japan, but i have just noticed that i forgot to write the postal code. does this matter? im worried that she wont receive my letter

Hi there

I've sent letters to Japan before and forgot to write the postal address, but the addressees still got it. If it's only the postal code missing, it shouldn't be a problem, provided that all the rest is correct. If the prefecture is written on there, that should already clear up a lot for the post office. So there's no need to worry about it I think.

In the future don't forget. The postal code is very important if they can't read your handwriting. The entire letter could be written in martian, but if the postal code is correct the post office can usually deliver. The postal code contains city, and location information to make it easier for postal delivery and sorting.

However since you left the postal code off, sometimes it might be a slight delay because it will have to be manually sorted, but as long as everything else is correct on the letter it should be ok.

Japanese postal sort machines read the character of address, if you didn't write postal code.

So you don't need to write postal code, if you didn't know that.

Here is the patent documents.
http://www.j-tokkyo.com/2007/B07C/JP2007-222747.shtml
http://www.j-tokkyo.com/1999/B07C/JP11226513.shtml