Can You Have Two Mortgages at the Same Time?
Yes, it can be done. It isn’t “illegal” or automatically blocked, but lenders will only allow it where the numbers work on paper and where your intention to sell the first property is credible.
In practice, they will want to understand whether you can genuinely carry both mortgages during the overlap period, even if that overlap is only meant to be short.
How Lenders Assess Affordability
There are two common approaches.
Some lenders effectively combine the two mortgage balances and assess the total against their income multiple and affordability model. Others treat your existing mortgage payment as a monthly commitment and deduct it before running affordability for the new loan.
Either way, the outcome is broadly the same: they assume you may have to support both mortgages at once, and they stress test accordingly. The online calculators can be a helpful sense check, but they tend to be optimistic because they don’t always model the overlap in the way a full application does.
Buying Before You Sell
If your property isn’t on the market yet, many lenders will still consider a purchase, but they often want reassurance around timing.
Some will only proceed if there is a clear plan to sell and may add conditions, such as evidence the property is marketed, or a requirement for simultaneous completion if affordability is tight. Where affordability is strong, they can be more relaxed, but it’s still lender-dependent.
Remortgage to Release Equity for the Deposit
Potentially, yes. On your current home: value around £210,000 with £108,000 outstanding is roughly 51% LTV.
That gives you scope to raise additional funds, subject to affordability, and use that as deposit on the new purchase. The key question is whether the lender will view the additional borrowing as sensible given you’re planning to redeem it shortly when the property sells.
Also, if you raise the borrowing and then immediately sell, you’ll want to avoid products with early repayment charges. That points towards no-ERC trackers or short fixed rates with low/no ERCs, depending on what’s available at the time.
Interest-Only During the Overlap
Your thinking is reasonable: interest-only can reduce the monthly cost during the overlap, and at 75% LTV it may be easier to find interest-only options than at higher LTVs.
But lenders won’t allow interest-only purely because it “feels cheaper” month to month. They will still want an acceptable repayment strategy for the interest-only portion. In an overlap scenario, that strategy is usually the sale of the existing property, but the lender will want that to be credible and time-bound.
Bridging Finance as an Alternative
Bridging can work when you need speed, or when a mainstream lender won’t tolerate the overlap on affordability. The appeal is flexibility and the lack of early repayment penalties.
The downside is cost, and the fact that you need a realistic exit. In your case the exit is the sale of the current home, so the big risk is simply timing: if the sale takes longer than expected, the cost can compound quickly.
For someone on £85k with relatively low existing LTV, you’d normally explore mainstream “buy before sell” routes first, and keep bridging as the fallback rather than the default.
The Practical Route That Usually Works Best
If you want to buy before you sell, the cleanest structure is often:
Raise deposit in a way that doesn’t trap you with ERCs.
Make sure the new mortgage is set up assuming a genuine overlap period.
Sell the existing property and then, if needed, reduce the new mortgage balance once sale proceeds land.
It can feel slightly clunky, but it avoids expensive short-term funding and keeps you in the mainstream mortgage market.
Why Speaking to a Broker Matters Here
This is one of those cases where the “right lender” is half the solution.
Some lenders are fine with non-simultaneous sale and purchase if affordability is strong. Others are rigid and will push you towards simultaneous completion, regardless of income. A broker can place it with a lender whose underwriting approach matches what you’re trying to do, and can also structure the borrowing to avoid avoidable ERC pain if the sale happens quickly.
