You would usually own copyright in text you have written unless: 

• You wrote it as part of your job in salaried employment; OR
• You transferred (assigned) your copyright to someone else (e.g. a publisher or a client).

You can own copyright in text that you agreed to write for a fee - for example, for a publisher, commissioning editor or client - if you didn't transfer your copyright as part of the agreement.

A transfer of copyright by a writer usually requires a written communication (e.g. a clause in a publishing contract or contributor agreement) that is signed by the writer. It can be an electronic signature.

You should check any documentation that relates to the works you register on the Member Portal.
You may also need to check with your publisher if you are unsure.