An external controller sits between your day-to-day bookkeeper and ownership as the oversight layer for your accounting function. The role isn’t to enter transactions or process payroll. It’s to make sure the work being done is accurate, the financial statements reflect reality, and the controls around your money are strong enough to catch problems before they become losses.

Month-end close review is the core task. After your bookkeeper finishes reconciling accounts and posting adjusting entries, the controller reviews everything. Are the bank and credit card reconciliations clean? Did accruals get posted correctly? Are there transactions sitting in suspense or uncategorized? Does the balance sheet tie out to supporting schedules? A controller catches the mistakes that would otherwise sit in your books for months and surface during tax prep or a lender review.

Financial reporting follows the close. The controller produces or reviews the statements that get sent to ownership, lenders, or investors. Numbers that look right at a glance can still be wrong. Revenue recognition, deferred income, prepaid expenses, and depreciation are common areas where bookkeepers cut corners or apply rules incorrectly. A controller makes sure those areas are handled properly so the statements are reliable enough to make decisions from.

Internal controls are the part most small businesses ignore until something goes wrong. Who has access to the bank accounts? Who can write checks? Who approves new vendors? Who reviews payroll before it runs? A controller designs and monitors these controls so one person can’t both create a vendor and pay it, or move money without anyone noticing. Small business fraud almost always comes from inside, and it almost always happens when one trusted person has too much unchecked access.

Oversight of in-house accounting is the other piece. If you have a bookkeeper or accounting clerk on staff, a controller gives them someone to ask questions of, reviews their work for accuracy, and catches issues before they reach you. Most owners don’t have the accounting background to know whether their in-house person is doing the job correctly. A controller does, and provides that accountability without you having to hire a senior accountant full time. External controller support is often the right fit when a business has outgrown one bookkeeper but isn’t large enough to justify a full-time hire at that level.

The role is different from a CFO. A CFO focuses on strategy, forecasting, fundraising, and major financial decisions. A controller focuses on the integrity of the numbers underneath all of that. You need accurate books before forecasting them makes any sense, and that’s what a controller delivers.

For most small businesses, this becomes useful in the $1M to $10M revenue range with an in-house bookkeeper already in place and ownership that needs to trust the numbers without auditing them personally. GMJ Accounting provides external controller support alongside the rest of our bookkeeping, tax and consulting services, so your in-house team has experienced backup and your financial statements get reviewed by someone with the credentials to stand behind them.