How to rename a child out of wedlock

[Alf]

Here is the problem, I have a single male guy which has a girl with a married woman, the child got the mother's family last name, is there any way to change her last name?

[Magz from Oz]

If the child is a member of your household, go to City Hall and select change name from the options pinwheel.  You get the option for first name, then last name.  Change the last name to whatever you want.

[Alf]

Forgot to mention they don't leave with me

[Pam]

Welcome to our Forum, Alf.

If you haven't already, go ahead and try the City Hall thing.  It might be possible to still change the name because it's the child of your sim.  Be sure to go during business hours.  If it doesn't work, you can still make it happen by doing a couple of tricky things in Edit Town.  Basically, you would change to the household where the child lives, have the mother change the child's name, then change back to your Sim.  Come back if you need instructions on how to do that. 

[Alf]

Welcome to our Forum, Alf.

If you haven't already, go ahead and try the City Hall thing.  It might be possible to still change the name because it's the child of your sim.  Be sure to go during business hours.  If it doesn't work, you can still make it happen by doing a couple of tricky things in Edit Town.  Basically, you would change to the household where the child lives, have the mother change the child's name, then change back to your Sim.  Come back if you need instructions on how to do that. 

LOL it works! I am sorry for not try that before come here to the forum, I knew I coulda change the name of my sims but never imagine I could change the name of a sim that don't live with me, to be honest, I've underestimated the game, really suprised it worked out, thank you so much, both of you!