Great question! It is my understanding what you will need to ask the Court in Mecklenburg County, NC for permission to change venue. There are certain things what you will be required show the court to support your application for a change in venue. However, the good news is that both you and the child now live another part of the North Carolina; and, from your post, it appears that your "ex" did not contest your relocation; nor did he file anything with the court to stop you from relocating.
Once the Court grants your motion to relocate and enters an order to that effect, the clerk of court (Meck. County), will prepare and send your case forward your "home county." Your case should then be assigned a new file number reflecting its status in Guilford county. Thereafter, your motion to modify will be decided by a Guilford county judge.
Legal disclaimer: Gregory Hunt it a licensed attorney in the state of North Carolina and can be reached at 704-325-5113. Any response made by Mr. Hunt upon this message board should not be construed as legal advice nor does it create an attorney/client relationship. Rather, Mr. Hunt's posts are intended as general information about the topic in question and not intended for any specific purpose or use. One should contact a qualified lawyer in their locale for specific follow-up and/or advice.
Sign up to receive a 3-part series of useful information and advice about child custody law.