Biweekly mortgage payments are one of the simplest mortgage acceleration strategies. Instead of 12 full monthly payments per year, you make 26 half-payments — equal to 13 full payments. That extra payment goes entirely to principal, reducing your balance and the interest that accrues on it.
On a $350,000 mortgage at 7.0%, monthly payments cost $487,000 in total interest over 30 years. True biweekly payments reduce that to approximately $435,000 — saving $52,000 in interest and paying off the loan in 25.5 years.
The Critical Caveat Most Lenders Do Not Explain
Not all servicers process biweekly payments as received. Many hold your half-payment until they have a full monthly amount, then apply both together at month end — exactly like a monthly payment. This eliminates the interest-saving benefit entirely. Before setting anything up, call your servicer and ask: "Do you apply each half-payment to my balance as received, or hold it until you have the full monthly amount?" You need the former.
How to Do This for Free
Many servicers charge $200–$400 setup fees for "biweekly programs." Ignore them. Two free approaches achieve the same result:
Method 1 — Annual extra payment: Pay monthly. Once a year, make one extra payment with the memo "apply to principal only." Schedule it January 1 or divide it into $50–$100/month extra.
Run the numbers for your situation: Use our free loan amortization calculator to see your exact monthly payment, total interest, and full amortization schedule.
Method 2 — DIY biweekly: Auto-transfer half your payment to a savings account every two weeks. Pay monthly from that account. When it accumulates an extra half-payment (happens twice a year), apply to principal.
Interest Savings Reference Table
| Loan | Rate | Monthly Payment | Years Saved | Interest Saved |
|---|---|---|---|---|
| $250,000 | 5.5% | $1,419 | 3.5 years | $28,000 |
| $350,000 | 6.5% | $2,213 | 4.0 years | $48,000 |
| $450,000 | 7.0% | $2,994 | 4.5 years | $66,000 |
| $600,000 | 7.5% | $4,195 | 5.0 years | $95,000 |
When This Is Not the Right Move
Extra mortgage payments are not always optimal. Skip this strategy if: you have high-interest debt (credit cards at 20%+ always come first), your rate is under 5.5% and you have a long investment horizon (stock index funds historically return more), you lack 3–6 months of liquid emergency savings, or you are not maximizing your 401(k) employer match.
Setting Up Correctly
- Confirm your lender applies half-payments immediately (not monthly batch)
- Confirm no prepayment penalties on your specific loan
- Always mark extra payments "apply to principal only" to prevent servicers from applying overpayment to next month’s scheduled payment
- Automate — biweekly strategies fail when they require manual action each month
Use the biweekly mortgage calculator to see your specific payoff date and interest savings before committing to a strategy.
