Two main reasons why a cat urinates outside its litter box.
1. Illness – When cats urinate around the house (specially males), they can be trying to tell you they’re sick. examine the urine, check if its slightly pinkish (blood). male cats are very prone to suffer from that kind of sickness.
2. Territorial Marking – This can be fixed easily by neutering them. A neutered cat will be much happier and you will too.
Also See – Cat Training