Skipton Remortgage/product transfer

Positivement

Hi my fixed term is shortly up and I wanted to understand the remortgage or product transfer process with Skipton. Not looking to change the term or borrowing therefore wanted to know whether I would have undertake another affordability check and if so what do they need to know. Would they need to see bank statements and wageslips or whether this would be done over the phone.
Since my original application my debt had increased however I've always met repayments therefore I am concerned that this may cause issues as I will be going in to the SVR and want to get a better deal.
Anyway had any experience dealing with them feedback woukd be appreciated. Thanks