Mia W.
Senior Writer
October 6, 2026
6 min
read
A rental income and expense spreadsheet should be built around transactions, not manually entered monthly totals.
If you receive $1,800 in rent, record the payment. If you spend $285 repairing a leak, record the expense. Then let formulas calculate the monthly and annual totals.
That gives you an audit trail instead of a workbook full of numbers that cannot easily be traced.
Use one row per income transaction.
DatePropertyUnitTypeAmountReferenceOct 1P0012ARent$1,650ACH-10021Oct 3P0012AParking$100ACH-10044
Possible categories include rent, parking, storage, utility reimbursements, and other tenant charges.
The important thing is to record each transaction separately, including partial payments and additional income, rather than overwriting a monthly total.
Use one row per expense.
DatePropertyCategoryVendorDescriptionAmountOct 4P001PlumbingABC PlumbingLeak repair$285Oct 7P001InsuranceXYZ InsurancePremium$140
Don't put every cost into a single “Expenses” category. Categorization is what lets you understand where the money is going.
Useful categories might include maintenance, insurance, property taxes, utilities, management fees, and professional services.
Give each property a stable ID.
Property IDAddressP00114 Oak StP00282 River Rd
Then use P001 and P002 throughout your transaction tables.
Stable identifiers help prevent inconsistencies when property names or addresses change. They also make it easier to summarize transactions by property.
Your summary should calculate:
The summary should pull its figures from the underlying transaction tables. Avoid manually entering totals that can become outdated as soon as another transaction is added.
If your Income table is an Excel Table named Income and its amount column is Amount, you can calculate total income using:
=SUM(Income[Amount])
To calculate total income for property P001:
=SUMIFS(Income[Amount],Income[Property ID],"P001")
To calculate repair expenses for property P001:
=SUMIFS(Expenses[Amount],Expenses[Property ID],"P001",Expenses[Category],"Repairs")
These formulas are much safer than manually changing a monthly total every time a payment arrives.
For reliable results, keep column names consistent and use the same property IDs and expense categories throughout the workbook.
Suppose a property receives $4,800 in rent and pays $1,150 in operating expenses.
That leaves $3,650 before financing and other cash movements.
If the mortgage payment is $1,900, the cash remaining after that payment is $1,750.
These are different measures, and keeping them separate matters.
For U.S. rental owners, the IRS applies specific rules to rental expenses, depreciation, and other tax items. A cash-flow spreadsheet should preserve the underlying transactions rather than assuming that a single “profit” figure answers every tax question.
A useful spreadsheet can include a document reference for each expense.
For example:
Document reference: 2026-INV-0047
The invoice or receipt itself can be stored separately in your document storage system.
This creates a simple chain:
Transaction → Reference → Supporting document
That is much more useful than storing a total such as “Repairs: $8,200” with no supporting detail.
Whenever possible, make document references unique so you can quickly locate the correct invoice or receipt during reconciliation.
A useful summary might look like this:
MetricOctoberRent scheduled$8,400Rent received$7,800Outstanding rent$600Operating expenses$1,950Cash flow before financing$5,850
The key is that these numbers should be formulas based on the transaction tables.
For example, rent received should reflect payments actually received during the reporting period. Outstanding rent should be calculated from the amounts due, payments allocated to those amounts, and any applicable adjustments.
Cash flow before financing is calculated by subtracting the relevant operating expenses from the income included in the same reporting period.
The spreadsheet is usually not the problem while the data is simple.
It becomes a problem when the landlord has to reconcile:
At that point, a centralized property-management system can remove repetitive administrative work and help keep records consistent.
RentDoo is designed for that stage: when landlords want their rental operations organized around connected property, tenant, lease, and payment records rather than a workbook that has to be manually maintained.
IRS — Rental Real Estate Income, Deductions and Recordkeeping
IRS Publication 527 — Residential Rental Property
https://www.irs.gov/publications/p527
