Amortization vs Interest-Only Loans in Commercial Real Estate
How your loan structure affects monthly payments, DSCR, cash flow, and total return, with side-by-side comparisons and guidance on when to use each.
Two fundamentally different approaches
Every commercial real estate loan requires a decision about structure: do you amortize the principal (pay it down over time) or pay interest only (keep the full balance outstanding)? This choice has cascading effects on your monthly cash flow, debt coverage ratios, equity build-up, and exit flexibility.
Neither is universally better. Amortizing loans build equity and reduce refinancing risk. Interest-only loans maximize cash flow and improve early-year returns. The right choice depends on your business plan, hold period, and risk tolerance.
Side-by-side comparison
Same deal, same property, same loan amount: different structure. Here's what changes:
Scenario
- Purchase price:
- $4,000,000
- Loan:
- $3,000,000 (75% LTV)
- Rate:
- 6.50%
- NOI:
- $340,000
- Hold period:
- 5 years
| Metric | Amortizing (25-yr) | Interest-Only |
|---|---|---|
| Monthly Payment | $20,256 | $16,250 |
| Annual Debt Service | $243,075 | $195,000 |
| Monthly Cash Flow (NOI - DS) | $8,077 | $12,083 |
| Annual Cash Flow | $96,925 | $145,000 |
| DSCR | 1.40x | 1.74x |
| Cash-on-Cash Return | 9.7% | 14.5% |
| Principal Paid Down (5 yr) | ~$283,000 | $0 |
| Remaining Loan Balance (5 yr) | ~$2,717,000 | $3,000,000 |
| Equity at Year 5 (at cost) | ~$1,283,000 | $1,000,000 |
Model both scenarios in DealWise AI
Enter your deal once and toggle between amortizing and interest-only to see exactly how each structure affects your DSCR, cash flow, and IRR, month by month over the full hold period.
When to use each structure
Amortizing loan
- Stabilized property with predictable cash flow
- Long-term hold (7+ years)
- Conservative strategy: want to build equity
- Preparing for refinancing at a lower LTV
- Lender requires amortization (most bank loans)
Interest-only
- Value-add deal: need cash flow for renovations
- Short-term hold (2-5 years) with planned sale
- Bridge loan during lease-up or stabilization
- Maximize early-year distributions to investors
- Syndication where cash-on-cash targets matter
The hybrid approach
Many commercial loans offer a hybrid structure: 1-3 years of interest-only payments followed by amortization for the remaining term. This is the most common structure for value-add acquisitions and bridge-to-permanent financing.
The logic is practical: during the first 1-3 years, you’re investing capital in improvements, leasing up vacant space, and stabilizing the property. Cash flow during this period is lower or negative. Interest-only payments keep your carrying costs down when you need flexibility most. Once the property stabilizes and NOI increases, the loan converts to amortizing payments, which the higher NOI can now support.
Example: a $3M loan at 6.5% with 2 years IO inside a 25-year amortization. Year 1-2 payment: $16,250/month. Year 3+ payment: $20,972/month. The $4,722/month increase is absorbed by the NOI growth from your value-add execution.
The hidden risk of interest-only
Interest-only loans look attractive on paper: higher cash flow, better DSCR, stronger cash-on-cash returns. But they carry a risk that amortizing loans don’t: you never reduce the principal.
When your loan matures, you owe the full original balance. If property values have declined or interest rates have risen, refinancing at the same or better terms may be impossible. This is exactly what happened to many commercial borrowers during rate hiking cycles. Properties that were comfortably financed with IO loans couldn’t refinance when terms expired because the new rate pushed DSCR below lender minimums, even though NOI hadn’t changed.
With an amortizing loan, you pay down approximately 8-12% of the principal over a typical 5-7 year hold. That principal paydown provides a cushion: you can refinance a smaller balance, which makes qualifying easier even if rates have risen.
The bottom line: interest-only is a tool, not a default. Use it when the business plan justifies it. Default to amortization when you don’t have a clear reason for IO.
Frequently asked questions
Does interest-only always mean higher returns?
In terms of cash-on-cash return, yes: lower payments mean more cash distributed. But total return (including equity build-up from principal paydown) can be similar or better with amortization. Interest-only boosts year-1 metrics but doesn't build any equity through the loan. Your total return depends on appreciation, NOI growth, and exit proceeds, not just annual cash flow.
Can I switch from interest-only to amortizing mid-loan?
If your loan has a built-in IO period followed by amortization (common in many commercial loans), the transition happens automatically per the loan documents. You generally cannot switch voluntarily from an amortizing loan to IO, or extend an IO period, without a loan modification, which requires lender approval and may involve fees.
How does loan structure affect my DSCR covenant?
Most commercial loans require maintaining a minimum DSCR (typically 1.20x-1.35x) throughout the loan term. With an IO loan, your DSCR is higher because payments are lower, but when the IO period ends and amortization begins, your payment jumps and DSCR drops. If NOI hasn't grown enough to cover the higher amortizing payment, you could breach your DSCR covenant. Always model the post-IO DSCR before signing the loan.
Which structure do lenders prefer?
Most traditional lenders (banks, credit unions) prefer amortizing loans because it reduces their risk exposure over time. CMBS and bridge lenders are more comfortable with IO periods because they're pricing for it. Agency lenders (Fannie/Freddie) offer IO on multifamily but typically require strong DSCR and LTV. In general, expect to pay a slightly higher rate or provide more equity for an IO structure.
Final thoughts
Loan structure is one of the most impactful decisions in commercial real estate underwriting. The difference between amortizing and interest-only affects every metric downstream: cash flow, DSCR, return on equity, and refinancing risk. Choose deliberately based on your business plan, not by default.
DealWise AI lets you model both structures side by side. Enter your deal, adjust the loan terms, and see exactly how amortization vs. interest-only affects your monthly cash flow, DSCR, IRR, and full hold-period projections, instantly.
Related guides
What is DSCR?
The coverage ratio that sizes your loan.
How to calculate DSCR
Step-by-step DSCR calculation guide.
Commercial loan terms explained
Every CRE financing term defined.
How to calculate cap rate
Cap rate formula with worked examples.
Amortization vs interest-only: key differences
The shorter read, with a $3.5M industrial deal modelled both ways.
Commercial loan payment guide
Where the $20,256 and $16,250 payments above come from.
Start analyzing deals free.
Model IO vs amortizing with full underwriting: NOI derived from your actual rent roll, then payment, DSCR and IRR across the whole hold.