Self-storage ancillary income: how to underwrite each line

What scales with occupancy, and what does not

The first underwriting decision for each line is what drives it. If income comes from tenants (a plan per tenant, a fee per late payment, a fee per move-in), it grows as occupancy grows. If it comes from something else (walk-in retail customers, truck renters who may not be storage tenants, a tower lease), it does not. Getting this wrong in either direction misstates stabilized NOI.

The Deal Analyzer and the NOI calculator follow this split. Tenant protection and fees go in one field that grows in proportion to occupied units as the facility leases up. Retail, truck and other income go in a second field that stays flat. If the seller's T12 lumps everything into “other income,” split it before you enter it.

Tenant protection and tenant insurance

Coverage for tenants' stored goods sold at the counter comes in two structures, and they are regulated differently:

• Tenant insurance is an insurance policy issued by a carrier. As Nate Kinet of SafeLease put it in Inside Self Storage in 2023, “many states allow self-storage owners to sell tenant insurance under a limited-lines license,” and the operator's ability to pay staff sales commissions or change rates “is governed by local legislation.” The Self Storage Association's 2017 overview of limited-lines licensing notes that requirements differ significantly by state, including required brochure language, employee training records and renewal schedules.
• Tenant protection plans are contractual arrangements under the rental agreement: the facility agrees to cover some loss to stored goods, typically backed by contractual liability insurance. Kinet describes them as not being regulated insurance contracts and as giving the operator more flexibility on pricing and staff incentives. In California, the state supreme court held in Heckart v. A-1 Self Storage (2018) that A-1's plan was not subject to regulation under the Insurance Code, because the arrangement was incidental to renting storage space. That decision is one state's law about one plan. Treatment elsewhere depends on the state, so have an attorney review the program you will run.

How to underwrite it

Build tenant protection revenue bottom-up, and check it against the T12:

Participation comes from the seller's management software (tenants enrolled ÷ occupied units). Owner's net per plan comes from the provider agreement: the plan price less the provider's share, or the commission if it is an insurance product. Kinet wrote that operators can expect the product to generate 8% to 10% of total revenue, “highly dependent on finding the right partner who offers a favorable revenue share.” He runs revenue at a provider of these programs, so treat that as one provider's estimate, not a benchmark. Your number should come from the facility's own enrollment report and contract.

Transfer at closing

Ask whether the seller's program can be assigned to you, whether you must change providers, and what happens to enrolled tenants if you do. A buyer who switches providers or structures may need to re-enroll tenants, and the existing rental agreements and state law decide what is possible.

Worked example: tenant protection at 78% and 90%

Suppose a 400-unit facility has 312 units occupied (78%), and you expect 360 (90%) at stabilization. Half of the tenants carry a protection plan, and the provider agreement nets the owner $7 per plan per month. Late fees, admin fees, retail and truck commissions are taken from the T12. All figures are hypothetical.

At 78%, 156 tenants carry a plan: 156 × $7 × 12 = $13,104. At 90%, 180 do: 180 × $7 × 12 = $15,120. Scaling the T12 figure by occupied units gives the same answer ($13,104 × 360 ÷ 312), which is what the Deal Analyzer does. Late and admin fees scale the same way; retail and truck revenue do not move.

When the seller has no program

Now suppose the seller offers no protection plan and you will start one at closing. Scaling does not help, because there is nothing to scale. If you assume only tenants who move in after closing enroll, the stabilized number depends on turnover, not occupancy. Suppose 120 of the 360 tenants at stabilization moved in after you bought, and half of them enroll: 60 × $7 × 12 = $5,040 a year, a third of the $15,120 you would get if every tenant were eligible. Underwrite the lower figure unless an attorney confirms you can offer the plan to existing tenants and you have a reasonable basis for expecting them to take it.

Late fees and admin fees

Late fees depend on how many tenants pay late and on the fee schedule. Two cautions. First, state law may limit them: Allicyn Bowley's 2022 Inside Self Storage article on fee strategy advises operators to check state statutes for the maximum late fee they can charge, and suggests that a reasonable maximum is typically no more than 20% of the tenant's monthly rent. Confirm the rule in the facility's state before you raise fees in your model. Second, late fees billed to tenants who never pay are not income. If the T12 shows late fees on an accrual basis, check how much was collected and how much was later written off at auction.

Admin fees, where they are charged at move-in (check the fee schedule), follow move-ins, not occupancy. During lease-up, move-ins run ahead of the stabilized pace, so fee income can temporarily exceed a simple occupancy-scaled figure. Scaling by occupied units is a slightly conservative approximation during lease-up, which is acceptable for underwriting.

Retail and truck rental

Retail

Locks, boxes, tape and moving supplies are sold at the counter. Underwrite the margin, not the sales: if the T12 shows retail sales as income, find the cost of goods sold, which may be buried in supplies or office expense. Retail generally tracks move-ins and walk-in traffic more than occupancy, so the Deal Analyzer holds it flat.

Truck rental

A facility that offers truck rental is often a dealer for a truck rental company, paid a commission rather than owning the trucks. U-Haul's dealer page says the company pays, on average, a 21% commission across all of its product lines. Other companies and individual agreements differ. The line in the T12 should therefore be commission income, not gross rental revenue. Ask for the commission statements and the dealer agreement, confirm whether the agreement transfers to a new owner, and check whether the trucks take parking spaces that could otherwise be rented. Truck rental is held flat in the model because it depends on the site's location and hours, not on storage occupancy.

Parking, cell towers and billboards

Some facilities rent outdoor parking for vehicles, boats and RVs, or lease part of the site to a cell tower or billboard operator. Treat outdoor parking as a unit type if spaces are rented month to month, because it behaves like storage. Treat tower and billboard income as a lease: read it, confirm the rent, term, escalations, termination rights and whether it is assignable, and hold it flat. A lease the tenant can terminate on short notice deserves a lower value than its current rent suggests.

Verifying ancillary income in the T12

1. Split the lines. Ask for tenant protection, late fees, admin fees, retail, truck and other income as separate lines, by month, for the trailing twelve months. See reading a T12 and rent roll.
2. Gross or net. Establish whether tenant protection is booked at the full plan price with the provider's share in expenses, or net. The same applies to truck commissions and retail. Either can be right; mixing them overstates income.
3. Tie to reports. Match tenant protection revenue to the enrollment report and the provider's statements, and fee income to the management software's fee report.
4. Tie to deposits. Compare total income to bank deposits. Income that does not reach the bank is not income.
5. Look for one-offs. Auction proceeds, insurance recoveries and a one-time fee change are not recurring. Leave them out of the run rate.
6. Check the rules. Confirm licensing for tenant insurance, the enforceability of your protection plan, and late fee limits in the facility's state with an attorney or the state insurance department.

Then enter the verified figures in the NOI calculator to see their effect on NOI and value. At a 7% cap rate, for example, every $1,000 of recurring ancillary income adds about $14,286 of value, which is why a lender or buyer will ask for the same evidence you did. These are estimates; confirm assumptions with your lender, CPA and attorney.

This guide is general education about self-storage underwriting, not investment, lending, tax or legal advice. Figures from third-party reports are cited with their dates and change over time.