Several people have asked me what, if anything, they can do with stories after they've been published. The answer is – it depends!
You'll need to check which rights (copyright) you've sold. This information will be in your contract if you have one, or will have been included in the guidelines (or competition rules) or on the letter or email of acceptance. If, as is the case with Yours magazine, you've sold all rights then you no longer own the copyright – you can't do anything at all as it's no longer your story. You can't sell it, put it on your blog, enter it in a competition. Nothing.
If, as is far more usual, you've sold first rights, or first rights with extensions, then you can offer the story elsewhere after it has been used by the first publication. There may be a time period before you are permitted to do that. Again, this information will be in your contract. (This is one reason it's so important to read and understand contracts before signing them.)
When submitting a previously published piece of work, you must also take into account the requirements of the publication you hope will accept it. Some will consider reprints without restrictions, but more usually they won't want work which has already been published wherever their publication is on sale. You may think that because you've only sold to a UK publication that the story will only have been published in the UK. That may not be the case. Depending on the terms of your contract, the buyer may have the rights to print it in other magazines within their group (at no extra cost to them) – and if they do, it's unlikely you'll be informed.
If the publication you hope to sell to only publishes work on a first use, first rights, or all rights basis, then you'll have to write something new. That doesn't just mean changing the title and character names!
Depending on the terms of the contracts, it may be possible to sell the same story multiple times. I do that whenever I can.
Assuming you haven't sold all rights, the buying publication have used the story and any exclusivity period has passed, then you may also publish the stories yourself.
I've just put together another collection of my short stories. The stories in With Love And Kisses originally appeared in My Weekly, YOU (South Africa), Allas (Sweden), Woman's Weekly, Woman's Weekly Fiction Special, That's Life (Australia), The Lady, Pages of Stories (Canada), Stories That Lift (U.S.) Cafelit, Ireland's Own, Take A Break's Fiction Feast, The Weekly News, or were placed in competitions.
Buy it (or read free with kindle unlimited) here.
See my other blog to discover how one of these stories was written at the instruction of Norah McGrath (former fiction editor for Take a Break's Fiction Feast), and to see my wearing a peculiar hat.