Depreciation Entry: What It Is & How Bookkeepers Record It

You purchase a $48,000 truck for your business in March. The truck is not an expense on your March P&L. It's a fixed asset on your balance sheet. But every month it's in service, a portion of that cost moves from the balance sheet to the P&L. That movement is the depreciation entry.

It's one of the most consistent adjusting journal entries in a bookkeeper's month-end workflow. Every business with vehicles, equipment, or furniture runs it. And yet it's one of the entries most likely to be missing from SMB books entirely.

What is a depreciation entry?

A depreciation entry is the monthly journal entry that allocates a portion of a fixed asset's cost to expense. It debits Depreciation Expense (increases the P&L expense) and credits Accumulated Depreciation (a contra-asset account that reduces the asset's net book value on the balance sheet). The asset's original purchase price stays on the books at cost. Only the accumulated depreciation account grows. For a $48,000 truck with a 5-year useful life and no salvage value, straight-line depreciation is $800 per month. That $800 moves from the balance sheet to the P&L each month for 60 months.

Key Takeaways

• Depreciation entries are monthly AJEs - they do not happen automatically; a bookkeeper or CPA must set up a fixed-asset schedule and book entries each period
• The asset stays on the books at original cost - only the Accumulated Depreciation contra-asset account grows; net book value = original cost minus accumulated depreciation
• Straight-line is the default for most SMB books - equal monthly amounts over useful life; more complex methods (accelerated, MACRS) are usually handled at the tax return, not in the GL
• Book depreciation and tax depreciation often differ - your books may show straight-line while your tax return uses §179 expensing or bonus depreciation; that difference is normal and expected
• A fully depreciated asset still shows on the balance sheet - original cost and accumulated depreciation both stay until the asset is sold or disposed; net book value hits zero, but the lines remain
• Mid-year acquisitions need a partial-month or half-year calculation - a truck purchased in October does not get a full annual depreciation amount in year one

The depreciation entry is part of the same double-entry bookkeeping system that governs every transaction in your GL. Understanding the entry structure prevents the most common errors in fixed-asset management.

What a Depreciation Entry Actually Is

Depreciation is the systematic allocation of an asset's cost over its useful life. It is not a cash transaction. No money moves. The journal entry simply transfers a portion of the asset's capitalized cost from the balance sheet to the income statement.

Two accounts move every month:

• Depreciation Expense (income statement): increases each period the asset is in service
• Accumulated Depreciation (balance sheet, contra-asset): increases by the same amount, reducing the asset's carrying value

The asset account itself never changes after purchase. The balance sheet shows gross asset cost on one line and accumulated depreciation below it. Net book value is the difference.

For the $48,000 truck at 5 years, $0 salvage: after 12 months, accumulated depreciation is $9,600 and net book value is $38,400. That figure is separate from what the truck would sell for in the market.

Straight-Line vs Accelerated Depreciation

Straight-line spreads the cost evenly across the useful life. It's the standard for most SMB books because it's predictable, easy to explain, and produces consistent monthly expense.

Formula: (Cost minus Salvage Value) divided by Useful Life in months = Monthly Depreciation

Accelerated methods front-load more depreciation into early years. The most common accelerated approach in practice is double-declining balance. It applies a depreciation rate of 2x the straight-line rate to the asset's remaining book value each period. Depreciation is higher in early years and lower later.

When do bookkeepers use accelerated on the books? Rarely for SMBs. Accelerated is more common on tax returns, not on GAAP or cash-basis books. Most small business bookkeepers run straight-line in the GL and let the CPA handle accelerated calculations at tax time.

Book Depreciation vs Tax Depreciation

This is the single most important concept to understand before touching a fixed-asset schedule.

Book depreciation is what you record in your GL. It follows a consistent method (usually straight-line) and shows up in monthly financial statements. It's designed to match asset usage with expense recognition over time.

Tax depreciation is what goes on the tax return. The IRS allows much faster write-offs through:

• Section 179 expensing: deduct the full cost of qualifying assets in the year of purchase, up to the annual limit. No need to depreciate over 5 or 7 years.
• Bonus depreciation: take a percentage of the asset's cost as an immediate deduction in year one.
• MACRS (Modified Accelerated Cost Recovery System): the IRS-mandated depreciation schedule for tax purposes, which uses accelerated methods and specific recovery periods by asset class.

These rules change with legislation and have limits, so your CPA handles the tax calculation. What matters for bookkeepers: the GL and the tax return will not match, and that difference is intentional. Your job is to keep book depreciation accurate and let the CPA reconcile the gap at year-end.

How to Record a Monthly Depreciation Entry

Before recording anything, you need a fixed-asset schedule. This tracks each asset's name, purchase date, purchase price, useful life, salvage value, depreciation method, and accumulated depreciation to date. A spreadsheet works. Most accounting software also has a fixed-asset module.

Once the schedule is set up, the entry is identical every month.

Example: $48,000 truck, 5-year life, $0 salvage, straight-line

Run this entry every month for 60 months. After 60 months, the account is fully depreciated. The truck stays on the books at $48,000 gross cost with $48,000 accumulated depreciation until you sell or dispose of it.

Most accounting software (QuickBooks, Xero) lets you set up recurring journal entries for depreciation. You book the schedule once and the entries post automatically. The risk is setting it and forgetting it while the actual asset situation changes.

Common Gotchas

Book and tax depreciation tracked in the same place. Keep them separate. The GL runs book depreciation. The fixed-asset tax schedule is a CPA deliverable. Mixing the two produces unreliable books and a messy reconciliation at year-end.

Fully depreciated assets left off the balance sheet incorrectly. When an asset reaches zero net book value, both the gross cost and accumulated depreciation stay on the books until you record a disposal entry. You cannot delete them or zero them out without the disposal. If you do, your balance sheet will show assets disappearing with no corresponding entry.

Mid-year acquisitions without a pro-ration. A truck purchased in March should not get a full year of depreciation if your system calculates annually. Use the monthly method from acquisition date or the half-year convention your CPA specifies.

Missing entries for disposed or sold assets. When a client sells a vehicle, remove both the gross cost and accumulated depreciation from the books and record any gain or loss. Leave the old asset on the schedule and phantom depreciation keeps posting each month.

How Growthy Handles Depreciation

Growthy flags large fixed-asset purchases for review instead of categorizing them to expense. When a transaction looks like a vehicle or equipment purchase, it surfaces for your attention.

That flag is the starting point: confirm it's a capital asset, set up the fixed-asset schedule, and book the monthly entry. Useful life, salvage value, and method stay with you. Alpha rate is $99/month with 5 companies per seat.

FAQ

What accounts are used in a depreciation entry?

Debit Depreciation Expense (income statement) and credit Accumulated Depreciation (contra-asset on the balance sheet). The expense account increases the period's costs. The contra-asset offsets the gross asset cost to show net book value.

What is the difference between depreciation expense and accumulated depreciation?

Depreciation Expense is the current-period charge. Accumulated Depreciation is the running total since the asset was placed in service. Expense hits the income statement each period; accumulated depreciation grows on the balance sheet until the asset is disposed.

How do I calculate straight-line depreciation for a monthly entry?

Take the asset's cost, subtract any salvage value, and divide by the useful life in months. A $48,000 truck with no salvage value and a 5-year life: $48,000 divided by 60 months = $800 per month. That $800 is your monthly depreciation entry for the life of the asset.

Why does my tax return show the truck fully expensed but my books show monthly depreciation?

Your CPA likely used Section 179 or bonus depreciation on the tax return to deduct the full purchase price in year one. Your books use straight-line depreciation spread over the useful life. These are two different calculations serving two different purposes. The tax return maximizes your current-year deduction. The books show the economic reality of the asset depreciating over time. Both can be correct simultaneously.

What happens to a depreciation entry when an asset is sold?

When you sell or dispose of an asset, stop booking depreciation and record a disposal entry. Remove the gross cost from the asset account, remove the accumulated depreciation from the contra-asset account, record any proceeds received, and recognize the gain or loss. Skipping the disposal entry leaves a ghost asset on your balance sheet with depreciation continuing to post each month.

Fixed assets are where SMB books go wrong quietly. No error fires when depreciation stops posting. The balance sheet just drifts from reality. A solid fixed-asset schedule and consistent monthly entries keep your financials accurate and your CPA's year-end work straightforward.

Get started with Growthy. For adjacent fixed-asset and close-cycle terms, see the full glossary.