Moving in with partner, worried about benefits

Thank you Gordon.
We spoke to the Jobcentre and Council where my partner lives and it does seem to be that we will have to claim UC. Both of the areas in which we live are full service UC areas and any change in circumstances triggers a UC claim. Therefore if he had moved here the outcome would be the same. I will ask them to direct me to the guidelines as you suggested. Thank you for your help. We will be making an appointment locally to try and talk through with an advisor what to do next.