Bad debt is billed rent that an occupied unit never pays and the operator writes off as uncollectible. Also called credit loss, it is a deduction from gross potential rent for tenants who owe but do not pay. Bad debt differs from vacancy because the unit is leased and occupied, yet the rent still fails to arrive.
How Is Bad Debt Calculated?
Bad debt is calculated as uncollectible billed rent divided by gross potential rent, expressed as a percentage. The formula is Bad Debt Rate = (Uncollected Billed Rent / Gross Potential Rent) x 100. It captures only rent that was owed by an occupying tenant and written off, not rent lost to empty units, which is vacancy loss.
An operator recognizes bad debt when collection efforts fail and the balance is charged off, often after a tenant skips, is evicted, or leaves owing back rent. Per Catalyst Equity Partners, underwriters commonly reserve 2% to 5% of gross revenue for bad debt in multifamily models, with the higher end reflecting weaker submarkets or workforce housing.
Input | Definition |
Gross potential rent | Total rent if every unit paid market rent |
Billed rent | Rent charged to occupying tenants |
Uncollected billed rent | Billed rent written off as uncollectible |
Bad debt rate | Uncollected billed rent / gross potential rent |
Bad debt is a collection failure, not a leasing failure. A property can be fully leased and still bleed income if occupying tenants stop paying, which is why economic occupancy accounts for bad debt even when physical occupancy reads full.
Why Bad Debt Matters
Bad debt matters because it reduces net operating income dollar for dollar and, at a market cap rate, destroys value at a multiple of the loss. Every dollar written off is a dollar that never reaches effective gross income, and because value equals NOI divided by a cap rate, a persistent rise in bad debt compresses value well beyond the annual cash shortfall.
The market context sharpens the point. Per Multifamily Dive, multifamily loan delinquencies reached 1.37% in the third quarter of 2025, the highest level since the global financial crisis era around 2010, and per Yield PRO, renter delinquency trends worsened through 2025. Elevated delinquency feeds directly into higher bad debt on operating statements.
Bad debt is also a leading indicator of screening quality. A property whose bad debt runs above the 2% to 5% underwriting band is often admitting tenants it should not, or failing to enforce pay-or-quit timelines. The number is a scorecard on both credit screening and collections discipline.
Example
A 100-unit property has gross potential rent of $1,800,000 per year. The property is fully occupied, but a group of tenants stops paying and, after failed collection, the operator writes off their balances. The table shows how the write-off drives the bad debt rate and the NOI impact.
Line | Calculation | Amount |
Gross potential rent | 100 units at market rent | $1,800,000 |
Uncollected billed rent | Written off after collection failed | $54,000 |
Bad debt rate | 54,000 / 1,800,000 | 3.0% |
Value impact at 6% cap rate | 54,000 / 0.06 | $900,000 |
The $54,000 write-off is a 3.0% bad debt rate, inside the underwriting band but not free. At a 6% cap rate, that annual loss corresponds to $900,000 of value if it persists. A building that looks fully occupied is quietly worth less because the rent is billed but not banked.
Variations and Edge Cases
Bad debt varies by asset class, market, and recovery timing. Per Catalyst Equity Partners, stabilized class-A properties often run credit loss near 0.5% to 2%, while workforce and value-add assets in weaker submarkets can push toward or past 5%, especially during downturns and periods of high unemployment.
Situation | Typical bad debt behavior |
Stabilized class-A | Low, roughly 0.5% to 2% |
Workforce or value-add | Higher, can approach or exceed 5% |
Economic downturn | Rises with unemployment and delinquency |
Post-eviction recovery | Partial recoveries reduce net write-off |
Gross-to-net presentation | Bad debt may appear as a revenue contra line |
The recurring error is confusing a gross bad debt figure with a net figure. Recoveries from collections agencies or security deposits offset write-offs, so the net bad debt an underwriter should model is lower than the gross charge-off.
Bad Debt vs Vacancy Loss
Bad debt is often confused with vacancy loss, but they describe different failures. Vacancy loss is rent lost because a unit is empty and unleased. Bad debt is rent lost because an occupied, leased unit does not pay. One is an absence of a tenant; the other is a tenant who owes and defaults.
The difference is empty versus occupied. A vacant unit produces no bill and no bad debt. An occupied unit produces a bill, and when that bill goes unpaid and is written off, it becomes bad debt. Both reduce effective gross income, but only bad debt signals a screening or collections problem rather than a leasing gap.
Frequently Asked Questions
What is a normal bad debt percentage in multifamily?Underwriters commonly reserve 2% to 5% of gross revenue for bad debt, with stabilized class-A assets often near 0.5% to 2% and weaker submarkets pushing toward or above 5%. The figure rises during economic downturns.
Is bad debt the same as vacancy?No. Vacancy loss is rent lost because a unit is empty and unleased, while bad debt is rent lost because an occupied, leased tenant fails to pay and the balance is written off as uncollectible.
How does bad debt affect property value?Bad debt reduces net operating income dollar for dollar, and because value equals NOI divided by a cap rate, a persistent write-off destroys value at a multiple. A $54,000 annual loss at a 6% cap rate is $900,000 of value.
Related Terms
Economic Occupancy
Effective Gross Income
Net Operating Income
Vacancy Rate
Break-Even Occupancy