Hi there fellows, I want to know if I will lose the backlink from other sites to my blog if I upgrade from free to paid domain. I have written few guest posts and I don't want to loose the backlinks.
You could do a permanent 301 redirect and all backlinks would point to New domain! However for the guest posts aspect, I would suggest you contacted whom you've written them for and let them know the change you've made in your domain (they would gladly edit the domain) knowing fully well you contributed to their Blogs. Take Care