CostYour new home's purchase closes a week before your old home's sale does, meaning you're technically carrying two mortgages — and two sets of payments — simultaneously for that overlap period.
7-day overlap, both mortgages active
| New mortgage payment (monthly, prorated for 7 days) | ~$650 |
| Old mortgage payment (monthly, prorated for 7 days) | ~$550 |
| Total overlap cost | ~$1,200 |
What usually happens
If your new purchase's closing date lands before your old home's sale closing date, you're technically responsible for both mortgage payments during the overlap — this is distinct from bridge financing, which covers the down payment gap; this is about carrying two ongoing mortgage obligations simultaneously, even briefly. The dollar cost is usually modest for a short overlap, but it's a real, sometimes-overlooked cost.
How to manage or avoid it
- Try to align closing dates when negotiating both transactions — the cleanest solution, though not always achievable depending on the other parties' constraints.
- Budget for a short overlap as a real, if modest, cost rather than being surprised by it.
- Confirm with both lenders how the overlap is handled — particularly whether your new mortgage's first payment is due immediately or on a delayed schedule, which affects the actual cash timing.
Who to ask
Your realtor and lawyer can help negotiate closing dates that minimize or eliminate the overlap when possible, and your mortgage broker can confirm exactly how your new mortgage's payment schedule interacts with a short overlap period. See your new payment amount on the mortgage payment calculator to budget the overlap accurately.