Key takeaways
What this article covers, in order:
- A small portfolio, a lot of moving parts
- Rent: record what's due, then what's paid
- Security deposits: not your money (yet)
- Repairs vs improvements: why the water heater matters
- Track each property separately
- Angela's Sep 2026, sorted properly
Bookkeeping for landlords rests on three habits: record rent when it's due and match it when it's paid, keep security deposits out of income because you'll likely hand them back, and split repairs from improvements so your numbers reflect what each property really costs. Do those three monthly, with a bank reconciliation at the end, and you'll know which units earn their keep.
A small portfolio, a lot of moving parts
Angela owns a duplex in Columbus and a single-family rental across town. Three tenants, three leases, one business checking account. On paper, her rent roll is $4,400 a month. Here's what actually showed up in her bank in Sep 2026:
- $1,450 from the upstairs duplex tenant on Sep 1, 2026
- $1,400 from the downstairs tenant, $50 short, on Sep 3, 2026
- $1,500 from the house tenant on Sep 6, 2026, plus a $50 late fee
- $1,500 on Sep 28, 2026: the security deposit from a new tenant taking over the house, because the old one moved out at month-end
And going out: a plumber ($385), a new water heater ($1,640), property insurance ($212), and $1,350 refunded to the departing tenant, keeping $150 for carpet cleaning.
If Angela just sorts deposits into "rent" and withdrawals into "expenses," her Sep 2026 looks like it had $5,900 of income and a lot of spending. It didn't. Let's untangle it.
Rent: record what's due, then what's paid
The cleanest approach for most landlords is to treat each month's rent like an invoice. On the 1st, record what each tenant owes. When the money comes in, record it as a payment against that charge.
Why bother, when you could just record deposits? Because it shows you who's behind. Angela's downstairs tenant paid $1,400 of $1,450. If she only records deposits, the $50 shortfall disappears. With rent recorded as a charge, it sits in her receivables until it's paid or she decides to write it off.
Late fees work the same way: charge them as their own line (often "late fee income"), then record the payment.
If you run a very small rental and prefer simple cash-basis books, recording rent when received is fine too. Just keep a separate rent roll so you can see shortfalls.
Security deposits: not your money (yet)
This is the one landlords most often get wrong.
When a tenant pays a security deposit, you haven't earned anything. You're holding their money against possible damage or unpaid rent, and in most cases you'll give it back. So it goes to a liability account, something like "Security deposits held." Not income.
When the tenant moves out, one of three things happens:
| What happens at move-out | How to record it |
|---|---|
| Full deposit returned | Debit security deposits held / Credit bank |
| Part kept for damage, rest returned | Debit security deposits held (full amount) / Credit bank (refund) / Credit income or reduce repair expense (amount kept) |
| Part applied to unpaid rent | Debit security deposits held / Credit rent receivable for the amount applied; refund the rest |
For Angela's turnover: the old tenant's $1,500 deposit comes off the liability. $1,350 goes back to the tenant from the bank. The $150 kept for carpet cleaning offsets the cleaning cost. The new tenant's $1,500 deposit goes on as a fresh liability.
Two practical points. Many states and some cities have specific rules about holding security deposits: separate accounts, interest, timelines for returning them. Those rules vary a lot, so check yours or ask a local attorney or CPA. And even where it isn't required, many landlords keep deposits in a separate savings account. It makes the liability on your balance sheet match real money in the bank, which makes reconciliation much easier.
Repairs vs improvements: why the water heater matters
The $385 plumber visit fixed a leak. That's a repair: it keeps the property in its existing condition. It goes straight to expenses.
The $1,640 water heater replacement is different. Replacing a major component generally counts as an improvement, which is recorded as an asset and expensed over time rather than all at once. The line between the two can be fuzzy, and there are rules and thresholds that may let you treat certain items differently.
Our advice: record obvious repairs as repairs, flag anything big or unclear, and let your CPA decide on the final treatment. In your books, a simple "Improvements – review with CPA" account is better than guessing. Clean books make tax time easier; your CPA handles the filing.
Track each property separately
With more than one rental, you'll want to know which one's actually profitable. The house might bring in more rent but eat it all in repairs. The duplex might be the steady earner.
Ways to keep properties apart:
- Name the property in every transaction memo ("Duplex – plumber," "House – insurance")
- Use sub-accounts for income and major expenses by property, if your chart of accounts allows
- Split shared costs (like one insurance policy covering two properties) using a consistent method
Some landlords open a separate bank account per property. That's tidy but adds reconciliation work. One business account plus disciplined memos is enough for most small portfolios.
Angela's Sep 2026, sorted properly
| Item | Amount | Where it goes |
|---|---|---|
| Rent received | $4,350 | Payments against rent charged ($4,400 charged; $50 still owed) |
| Late fee | $50 | Late fee income |
| New security deposit | $1,500 | Security deposits held (liability) |
| Old deposit refunded | $1,350 | Reduces security deposits held |
| Deposit kept for cleaning | $150 | Offsets cleaning expense |
| Plumber | $385 | Repairs, duplex |
| Water heater | $1,640 | Improvements, house (CPA to confirm) |
| Insurance | $212 | Insurance, split across properties |
Real rental income for the month: $4,400 of rent charged plus $50 in late fees. Not $5,900.
Monthly landlord checklist
- [ ] Rent charges recorded for every tenant on the 1st
- [ ] Rent payments matched; shortfalls visible in receivables
- [ ] Late fees charged and matched
- [ ] Security deposits received or returned recorded against the liability
- [ ] Deposits held balance matches the deposit account (if you use one)
- [ ] Every expense tagged to a property
- [ ] Large items flagged as possible improvements
- [ ] Bank and credit card accounts reconciled to statements
How HelloBooks helps
HelloBooks gives landlords the pieces for this routine without property-management overhead. Invoices handle monthly rent charges, AR aging shows who's behind, and unlimited email payment reminders handle the nudging. You can connect most US banks and credit cards so rent deposits and repair payments come in on their own, or import a CSV statement if your bank isn't available for a feed. Your Balance Sheet shows the security deposits you're holding as a liability, right next to the cash.
Free fits a landlord with one account and modest volume: one live bank feed, up to 200 transactions a year. If you hold deposits in a separate savings account, you'll want a second connection, and Starter ($14.99/month) adds three bank connections plus recurring invoices so rent charges create themselves each month. You can also invite your CPA into the same books at year-end. More on our landlord page and on recurring invoices.
FAQs
Is a security deposit income for a landlord?
No, not when you receive it. It's a liability because you'll likely return it. It becomes income only if, and when, you keep part of it under the lease.
Should I keep security deposits in a separate bank account?
Some states require it. Even where they don't, it's a good practice because your liability then matches real cash, which simplifies reconciliation.
How do I know if something is a repair or an improvement?
Repairs restore something to working order; improvements add value, extend life or replace a major component. The rules have nuance, so record clear repairs as expenses and flag big items for your CPA.
Do I need a separate bank account for each rental?
No. One business account with every transaction tagged to a property works for most small portfolios. Separate accounts are cleaner but mean more reconciling.
How should I record a partial rent payment?
Record the payment against that month's rent charge. The unpaid portion stays in receivables so you can follow up or decide how to handle it.
Three tenants or thirty, the same three habits keep the books honest.
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