Debt, new home and everything

Can anyone give me advice on how they manage when one person in a relationship has debt and the other doesn''t? As in another thread I asked the question is my house safe if my new partner moves in as he had debt, he is paying back money from a repossession. This is through his x partner doing a runner and unknown to him not paying the mortgage and hiding letters and communications. How do other people manage and get round this as we want to make a home together. Even if we are not married is our credit rating linked? Am at the moment downsizing to a new property part of the money am putting down from my divorce and the other is a mortgage. We are going to have an agreement drawn up regarding this. Any advice and thoughts welcome.

As a general rule, married people or cohabitants who live together are not liable for each other''s debts. There are a few small exceptions to this, notably Council tax, but this is the general principle.
You could be responsible if you signed for the debts or agreed to act as guarantor.
But it can ( and does ) happen that if, say, a husband goes bankrupt, and the family home is in joint names, then the family home could be sold to realise the husband''s share.
If a debtor has assets there is always the possibility that at least some of those assets could be taken to pay the debts.
But as far as I can see, you are planning to take in a new partner but the whole of the house will remain yours. Your own assets can''t be taken to pay his debts solely by reason of the fact that you live with him.
If you have any specific concerns, legal advice is recommended. But these are the general principles.
LMM