General ledger running balances: the balance-column account

The T-account is the classic way to picture a ledger account: debits on the left, credits on the right, balance worked out at the end. It is perfect for learning and for quick sketches. Real ledgers, on paper or in software, usually look different. They use the balance-column (or running-balance) form, where each posting is a row with a date, a description, a debit or credit amount, and the balance after that posting. Anyone looking at the account can see what it stood at on any date, not just at month end.

This page explains the balance-column form, the one rule that drives every running balance, and how it works for accounts with debit balances and accounts with credit balances, using numbers from our practice set.

The layout

A balance-column account has these columns:

• Date of the transaction.
• Description (or explanation), often with a posting reference to the journal page or entry number it came from.
• Debit and Credit: each row has an amount in one of them.
• Balance: the account's balance after this row. Some ledgers have two balance columns, debit balance and credit balance; others have one, with the side implied by the account's normal balance.

The first row is usually the opening balance brought forward from the previous period.

The one rule: normal balance decides the direction

Every account has a normal balance, the side on which increases are recorded:

• Debit-balance accounts: assets (Cash, Accounts Receivable, Supplies, Equipment), expenses and Owner's Drawing. A debit adds to the balance; a credit subtracts.
• Credit-balance accounts: liabilities (Accounts Payable, Notes Payable), Owner's Capital and revenues. A credit adds to the balance; a debit subtracts.

So the running balance is always:

New balance = previous balance + amount on the normal side − amount on the other side

That is all there is to it, but it is easy to slip on credit-balance accounts, where the instinct to "add debits" leads you the wrong way.

Worked example: a debit-balance account (Cash)

Here is one of the practice problems, Pine Street Dental's Cash account for August:

Row by row:

1. $7,255.00 − $4,135.00 = $3,120.00 (a credit to Cash: money out).
2. $3,120.00 + $2,968.00 = $6,088.00 (a debit: money in).
3. $6,088.00 + $123.00 = $6,211.00.
4. $6,211.00 + $1,201.00 = $7,412.00.
5. $7,412.00 − $4,002.00 = $3,410.00.

A quick check: the opening balance plus total debits minus total credits should equal the last balance. Debits total $4,292.00 and credits $8,137.00, so $7,255.00 + $4,292.00 − $8,137.00 = $3,410.00. It agrees.

Worked example: a credit-balance account (Accounts Payable)

Now the same idea for a liability. Accounts Payable has a normal credit balance, so credits (new bills) increase it and debits (payments, supplier credit memos) decrease it:

The arithmetic is identical to the Cash example; only the columns have swapped. The supplier payment is a debit that reduces the balance. If you added it, you would get $11,390.00, a payable that grows every time you pay a bill, which is a clear sign of the wrong direction.

What an unusual balance tells you

Most accounts never cross zero. Cash should not go negative in the books (an overdraft is a liability to the bank, normally shown separately). Accounts Payable should not go into a debit balance unless a supplier has been overpaid. If your running balance turns negative, the most likely explanation is an arithmetic slip or a posting to the wrong column, so re-check before you assume the business really overpaid someone. In this lesson every account stays on its normal side, which makes a negative balance a reliable warning that a step has gone wrong.

Why bookkeepers prefer running balances

• Balance on any date. If a customer asks what they owed on the 15th, or the bank asks for your cash position mid-month, the answer is on the row for that date.
• Errors surface early. An implausible balance (a negative payable, a sudden jump) stands out row by row instead of hiding until month end.
• It matches statements. Bank statements, customer statements and supplier statements all use running balances, so reconciling them against the ledger row by row is straightforward.
• It is what software shows. Account registers and ledger reports in accounting software use this layout. Knowing how each balance is built helps you trust, and question, what the software displays.

Running balances in a spreadsheet

If you keep a ledger in a spreadsheet, the same rule becomes one formula copied down the balance column. For a debit-balance account with debits in column C, credits in column D and balances in column E, the balance on row 3 is the balance above plus the debit minus the credit, and for a credit-balance account it is the balance above plus the credit minus the debit. Writing it once and filling down avoids retyping errors, and blank cells count as zero. The Excel for Accounting course practises this kind of formula; this lesson focuses on the bookkeeping logic behind it.

From running balances to the trial balance

At month end, the last balance in each account is the figure that goes onto the trial balance, in the debit column for debit-balance accounts and the credit column for credit-balance accounts. Because the balance column already carries the running total, preparing the trial balance becomes a matter of reading the last row of each account. That is one more reason the balance-column form replaced T-accounts in day-to-day bookkeeping: the month-end work is mostly done as you go.

The same last balance is also what you compare with outside evidence. Cash's closing balance is compared with the bank statement in a bank reconciliation. Accounts Receivable's is compared with the total of the customer accounts, and Accounts Payable's with the supplier accounts. Supplies and inventory balances are compared with a physical count. When the comparison does not match, the rows of the balance-column account are where you start looking, because each row shows exactly when the balance changed and by how much.

A short checklist

• What is the account's normal balance, debit or credit?
• Did you start from the opening balance, not from zero?
• For each row: is the amount on the normal side (add) or the other side (subtract)?
• Does every balance stay on the normal side? If one turns negative, re-check the row above.
• Does opening + normal-side total − other-side total equal your last balance?

Two-column balance layouts

Some ledgers show two balance columns, one headed Debit and one headed Credit, and write each balance in the column for its side. That layout handles the rare account that crosses zero without needing a minus sign: the balance simply moves from one column to the other. The arithmetic is the same as the single-column form used in this lesson, where the account's normal side is stated in the column heading and every balance stays on that side.

Common mistakes

1. Applying debits and credits the wrong way round on a credit-balance account. For liabilities, equity and revenue, credits add.
2. Adding every amount. A running balance is not a running total of activity; amounts on the opposite side subtract.
3. Starting from zero instead of the opening balance.
4. Carrying a slip forward. One wrong balance makes every later one wrong too. Use the end-of-month check: opening + normal-side total − other-side total = closing.

How the practice works

Each exercise generates an account with an opening balance and a month of postings. You type the balance after each posting and press Check; every balance is compared with one computed from the same postings, and the two common mistakes above are recognised with their own feedback. The lesson starts with Cash, moves to Accounts Receivable, then a credit-balance account, Accounts Payable, and finishes with a longer revenue account that includes a correcting debit.