> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt
> Use this file to discover all available pages before exploring further.

# Debits and credits

> The most counterintuitive idea in accounting, made simple. Why 'debit' doesn't mean subtract and 'credit' doesn't mean add — explained with T-accounts and double-entry.

Here's the concept that trips up almost everyone the first time: **debits and credits**. The trouble is that the words *feel* like they should mean "take away" and "add" — because that's how your bank uses them. In accounting, they mean something different, and once it clicks, it stays clicked.

## Forget what your bank taught you

***

When your bank says it **credited** your account, your balance went **up**. So you'd reasonably assume *credit = add* and *debit = subtract*.

But the bank is talking from **its** point of view, not yours. Your money is something the bank **owes** you — a liability on their books. The words flip depending on whose record you're reading. That's the source of all the confusion.

So drop the everyday meaning entirely. In accounting:

* **Debit** simply means **the left side** of an account.
* **Credit** simply means **the right side** of an account.

That's it. They're just directions — left and right — not "minus" and "plus." Whether a debit raises or lowers a number depends on **what kind of account** it is.

## The T-account: left and right

***

Accountants picture every account as a big letter **T**. Debits go on the left, credits go on the right.

```mermaid theme={null}
flowchart TB
    subgraph T["Cash (an asset)"]
        direction LR
        D["DEBIT — left side<br/>increases an asset<br/><b>+ $500</b>"]:::debit
        C["CREDIT — right side<br/>decreases an asset<br/><b>− $200</b>"]:::credit
    end
    T --> B["Balance: <b>$300</b>"]:::bal
    classDef debit fill:#dbeafe,stroke:#2563eb,color:#1e3a8a
    classDef credit fill:#fde68a,stroke:#d97706,color:#78350f
    classDef bal fill:#f3f4f6,stroke:#6b7280,color:#111827
```

For an **asset** like Cash: debits (left) **increase** it, credits (right) **decrease** it. Put in \$500, take out \$200, you're left with \$300.

But flip the account type and the behavior flips too:

| Account type                   | Debit (left) does | Credit (right) does |
| ------------------------------ | ----------------- | ------------------- |
| **Assets** (what you own)      | Increase          | Decrease            |
| **Liabilities** (what you owe) | Decrease          | Increase            |
| **Equity** (what's yours)      | Decrease          | Increase            |

Notice the pattern: assets behave one way, and liabilities and equity behave the **opposite** way. That mirror image is no accident — it's exactly what keeps *Assets = Liabilities + Equity* in balance.

## Why this strange system exists

***

You might ask: why not just use plus and minus? Because debits and credits do something a single sign can't — they **force every transaction to balance**.

The iron rule of accounting is: **total debits must always equal total credits.** Every time you record something, the left side and the right side have to match. If they don't, you've made a mistake, and the books will tell you so.

Take a real transaction. **You buy a \$500 laptop with cash.** Two accounts move at once: Equipment goes up (a \$500 *debit*) and Cash goes down (a \$500 *credit*). One event, two entries — and the totals match exactly:

```mermaid theme={null}
flowchart LR
    E["Equipment (asset)<br/>DEBIT <b>+$500</b>"]:::debit
    C["Cash (asset)<br/>CREDIT <b>−$500</b>"]:::credit
    E --- BAL{{"Total debits $500<br/>= Total credits $500"}}:::bal
    C --- BAL
    classDef debit fill:#dbeafe,stroke:#2563eb,color:#1e3a8a
    classDef credit fill:#fde68a,stroke:#d97706,color:#78350f
    classDef bal fill:#dcfce7,stroke:#16a34a,color:#14532d
```

The money didn't vanish — it changed form, from cash into equipment. Both accounts are assets, so the debit raises one while the credit lowers the other, and the two \$500 entries cancel out. That's the rule made concrete.

This is the engine behind **double-entry bookkeeping**: one event, recorded as a debit in one account and a matching credit in another. Money never just appears or disappears — it always moves *from* one place *to* another, and the debits and credits prove it.

<Note>
  **See also in Core Banking**

  See what debit and credit really mean from the ledger's side in [How money is recorded](/en/fundamentals/core-banking/double-entry-explained).
</Note>

## In short

***

* **Debit** means the **left** side of an account; **credit** means the **right** side. They are directions, not "subtract" and "add."
* Whether a debit or credit raises a balance depends on the **account type** — assets behave opposite to liabilities and equity.
* The system exists so that **debits always equal credits**, which keeps the books balanced and nothing unaccounted for.

<Note>
  **Next up**

  Debits and credits only make sense as a pair. See how they work together in [Double-entry bookkeeping](/en/fundamentals/accounting/double-entry-bookkeeping).
</Note>