# How to catch up on bookkeeping when you are months behind

A plain guide to catching up on months of bookkeeping: get every statement, set opening balances, then sort and reconcile one month at a time.

Published November 5, 2026.

Bookkeeping is the record of the money that comes into and goes out of your business. When you do not do it for some months, the work piles up. That pile is called a backlog.

A backlog feels big, but your bank already has a record of every dollar that moved, in order. So does your card company and your payment app. To catch up, you do not rebuild the past from memory. You sort a record that already exists.

## The short version

- Find the last date your books were correct. Your backlog starts the day after.
- List every account that business money went through.
- Download every statement for every month of the backlog.
- Set each opening balance from a statement, not from memory.
- Work one month at a time, oldest first, and reconcile each month before you start the next.
- Look for receipts only for the large and unusual items.

## Words to know

**Statement.** The monthly record from your bank, card company or payment app. It lists each transaction and the balance at the end of the month.

**Opening balance.** The amount in an account on the day your backlog starts.

**Categorize.** Give each transaction a type, such as "supplies" or "insurance". See [how to categorize bank transactions](https://rightobooks.com/blog/how-to-categorize-bank-transactions/).

**Reconcile.** Check that the balance in your books equals the balance on the statement for the same date.

**Transfer.** Money that moves between two of your own accounts. It is not income and not an expense.

## Decide where the backlog starts

Start on the day after the last date your books were reconciled. If they were never reconciled, start on the first day of the tax year you must file. For most sole proprietors that is January 1. The IRS says: "Generally, individuals must adopt the calendar year as their tax year" ([Publication 538](https://www.irs.gov/publications/p538)). If your business started later, start on the day it started.

If a tax payment is near, do the months that payment needs first. The [small business tax deadlines for 2027](https://rightobooks.com/blog/small-business-tax-deadlines-2027/) list the dates.

## Find every account

Write down every place business money went. Include:

- business checking and savings,
- every card you used for business, also a personal card,
- payment apps and processors,
- loans and lines of credit.

A missing account is a common reason why a month does not balance.

## Get every statement

Download each statement for each month. Where the bank gives a CSV or OFX file, take it, because the data comes over exactly. Also keep the PDF statements. They show the end balance.

Make a small grid: accounts down the side, months across the top. Put a tick in each box when you have that statement. A gap in the grid is a gap in your books.

## Set opening balances

Take each opening balance from the statement for the day before your start date. A card balance is money you owe, so it goes on the other side from cash.

## Work oldest month first

For each month, do all accounts before you go to the next month:

1. Bring in every line from each statement.
2. Match transfers first. A card payment from checking shows on two statements. It is one event and it is not an expense.
3. Record money you took out as an [owner draw](https://rightobooks.com/blog/how-to-record-owner-draws-and-contributions/), and money you put in as an owner contribution.
4. Categorize repeat lines (insurance, phone, a regular supplier) and make a rule for each.
5. Categorize the rest. Put lines you cannot identify in an "Ask accountant" category, and continue.
6. Reconcile each account to the statement's end balance.

When you work oldest first, each month starts from a balance that you know is correct. Errors cannot carry forward. For card accounts, see [how to reconcile a credit card statement](https://rightobooks.com/blog/how-to-reconcile-a-credit-card-statement/).

## Which receipts to look for

Statements show who you paid, how much and when. They do not show what you bought and why. The IRS accepts account statements as proof of payment ([Publication 583](https://www.irs.gov/publications/p583)). But it also says: "Proof of payment of an amount, by itself, does not establish you are entitled to a tax deduction."

So look for receipts for large purchases, equipment, [payments to contractors](https://rightobooks.com/blog/track-payments-to-contractors/), meals, travel and gifts. Email receipts and order histories fill most gaps. For more, see [how to track business expenses for taxes](https://rightobooks.com/blog/how-to-track-business-expenses-for-taxes/).

## An example

Diego runs a mobile dog grooming business. (He is an example, not a real person.) It is August, and his books were last reconciled on December 31.

On the first evening, he listed three accounts: business checking, a business card and his card payment app. Then he remembered a personal card that he used twice in February. He added it. He downloaded statements for January to July and found that one June statement was missing.

On the second evening, he set his opening balances from the December 31 statements and did January and February. He made rules as he went.

On the third and fourth evenings, the rules did about half of the work. April was $64.00 out. He found a $32.00 supplier refund that he had entered as a charge. He changed it, and April reconciled. At the end, 14 lines were in "Ask accountant". He found 11 in his email and took 3 to his accountant.

His books were reconciled to the cent through July 31.

## A Righto tip

In [Righto](https://rightobooks.com/), you can import a full year of bank statements at one time, as CSV, OFX or PDF files. Righto is a free accounting app for Mac. Your data stays on your Mac. You can also ask your own AI agent, such as Claude Code, to import the statements, match the transfers and categorize repeat lines. See [how agents work with Righto](https://rightobooks.com/agents/).

## Common questions

**How far back must I go?**
To the last date your books were reconciled. If they never were, go to the first day of the earliest tax year that you must still file.

**My bank shows only recent statements online. What do I do?**
Ask the bank for the older statements. Until they come, use PDF statements that you saved or got by email.

**Do I need a receipt for every coffee?**
No. You need records that support what you claim. Start with the large and unusual items.

## What to do now

1. Find the last date your books were correct.
2. Make the grid of accounts and months.
3. Download statements until each box has a tick.
4. Set opening balances from the statements.
5. Do the oldest month first, and reconcile it before you go on.

[Righto](https://rightobooks.com/download/) is free, easy to use and needs no account.

## Sources

- [Publication 538, Accounting Periods and Methods](https://www.irs.gov/publications/p538), IRS
- [Publication 583, Starting a Business and Keeping Records](https://www.irs.gov/publications/p583), IRS