Buying together when one of you has something on their file.

What a joint application actually means

The lender assesses you as one unit, because you would both be liable for the whole debt rather than half each. Most automated systems then take the more cautious of the two views when the files disagree — which is how an application with two solid incomes gets stopped by one entry belonging to one person.

It cuts both ways, though, and people forget the good half: two incomes usually mean considerably more borrowing than one, so a joint application with a specialist lender is often better than a sole application with a mainstream one. Which of those wins is arithmetic, and worth doing properly before deciding anything.

Do this before you apply anywhere

• Both of you check all three credit files. Not just the one who expects a problem — the other file frequently turns up something forgotten.
• Write down dates and amounts. When it happened, how much, whether it is settled. Those three facts decide most of what follows.
• Do not make a speculative application to see what happens. That is the single most expensive way to find out, because it leaves a footprint on both of you.
• Check whether you are financially linked. A joint account or shared loan links your files; living together does not.

The three routes, plainly

Apply jointly to a lender that reads both files. Often the stronger position: you both stay on the mortgage and the borrowing reflects both incomes. Expect a narrower choice of lenders and pricing above the high street.

Apply in one name. Perfectly legitimate, and sometimes right. The borrowing is based on one income, which is usually the constraint. The other person's stake can still be protected through a declaration of trust — but how the property is held and what happens if you separate are questions for a solicitor, and worth answering before rather than after.

Wait, on purpose. If an entry is close to dropping off or about to cross a lender's cut-off, a short delay can change the terms significantly. Only worth doing with a date attached, which I can usually give you on the phone.

If one name is on the mortgage, who owns the house?

This is the question the sole-application route always raises, and it deserves a proper answer rather than "see a solicitor" — although a solicitor is genuinely who decides it. The mortgage and the ownership are related but not identical. If only one of you is on the mortgage, the lender will normally require only that person on the legal title — but the other's contribution can still be protected as a beneficial share, recorded in a declaration of trust that a solicitor draws up.

In England and Wales a property held by two people is held one of two ways. As joint tenants, you both own the whole of it, and if one of you dies the other takes it automatically — that is survivorship, and it happens regardless of what a will says. As tenants in common, each of you owns a defined share, those shares can be unequal, and each passes under a will rather than automatically.

Where one person has put in most of the deposit, or one is named on the mortgage while both contribute to the payments, tenants in common is the arrangement a solicitor will often discuss. The arrangement is recorded in a declaration of trust — a document setting out who owns what proportion, who pays what, and what happens if the place is sold. A restriction can also be entered at the Land Registry so it cannot be sold without both of you agreeing.

The version of this conversation that costs money

If the relationship ends, the mortgage takes no interest in who is living there or who has been paying. The person named on it is liable for the whole payment, and a lender will pursue that person for all of it, not half.

The person not on the mortgage may still have a beneficial interest in the property if they contributed to it — but establishing that afterwards means two sets of solicitors, evidence of what was paid and when, and an argument neither of you wanted. A declaration of trust written at the outset costs a fraction of that and takes an afternoon.

I raise it because it is the part nobody brings up while everyone is excited about the house, and because it is the one element of this that is genuinely cheap to get right at the start and genuinely expensive to fix later. Ask your conveyancer about it when you instruct them — not after completion.