Ten Common Mistakes New Accountants Make

This list comes from files handed to me for correction or defence, and the root cause almost always traces back to an accountant's first years. If you are starting out, read each item as a working habit rather than a technical point, because that is where nearly all of these errors originate.

Deadline and filing mistakes

1. Not keeping statutory deadlines in a calendar

The most common and the most expensive. A wrong entry can be fixed; a late filing penalty is a percentage of the amount involved and is rarely negotiable.

Details change from year to year, so rebuild the calendar each spring from the tax authority's latest announcement. The quarterly obligation is detailed in the quarterly transaction report guide.

Recording and evidence mistakes

2. Deleting and rewriting entries

A dangerous habit encouraged by permissive software. Deleting an entry and re-posting it with an earlier date destroys the audit trail and reads as manipulation during an assessment. Post a correcting entry with a clear narrative instead. In statutory ledgers, alterations and erasures are among the grounds that can lead to the books being rejected and the file moved to a deemed assessment.

3. Trusting the initial software setup

The system calculates exactly what you configured. An incomplete chart of accounts, a wrong tax rate or an undefined warehouse produces errors quietly for months. Every quarter, calculate one sample by hand and compare. Getting the account structure right on day one is the cheapest thing you can do for the years that follow.

Control and inventory mistakes

4. Letting reconciliations slide

Bank reconciliation is the simplest control available and the first thing beginners postpone. Three months behind, finding the difference becomes several times harder. The simple rule: reconcile every main account monthly, in the first week of the following month.

5. Mixing the owner's personal account with the company's

To keep things moving, a beginner often books the owner's personal withdrawal as an expense. That makes the cost non-deductible and creates problems when bank transactions are reviewed. The correct route is the partners' or directors' current account. See separating personal and company accounts.

6. Recording expenses without acceptable evidence

An informal invoice, a handwritten receipt or an untraceable cash payment is removed during assessment and the tax comes back to the company. The simple rule: an expense without producible evidence is not an expense. Three general conditions apply: the cost was actually incurred, it relates to the business activity, and producible evidence exists. Miss one of the three and arguing with the inspector is pointless.

7. Overlooking withholding obligations

Beginners think only about the company's own tax and forget that on certain payments the company must withhold and remit tax. Contracting payments under Article 104 are the classic case, and the liability for failing to withhold stays with the payer. The rate is set by regulation and the scope is wider than most beginners expect.

8. Inventory that exists only on paper

Recording purchases and sales without real stock control makes product cost meaningless. If system quantities are never reconciled to a physical count, reported profit is just a number. Two related errors are common: recording a purchase with no goods receipt, and issuing a sale with no goods issue. Both create variances that stay hidden until the year-end count.

Behavioural mistakes

9. Guessing instead of asking

New accountants fear looking inexperienced, so they guess. One guess in classification repeats until year end, and correcting it costs ten times what asking would have. The rule I suggest to teams: any uncertainty lasting more than fifteen minutes gets asked.

10. Not reporting bad news

The worst outcome is a manager learning about a tax problem from the assessment notice rather than from their accountant. Report any error you find the same day, with a proposed correction. In my experience managers forgive a reported error and never forgive a concealed one.

A weekly routine that prevents most of this

1. Monday: review statutory deadlines falling in the next two weeks.
2. Reconcile the main bank accounts, even partially.
3. Review the week's entries for narrative quality and attached evidence.
4. Chase any expense recorded without documentation.
5. Reconcile the week's sales to issued invoices and submitted reports.
6. Log open questions and raise them with your supervisor.
7. Write down one thing you learned this week.

It looks time-consuming and in practice takes under two hours a week, while preventing more errors than any training course. For the wider picture, see the skills that set a professional accountant apart.

If you have just taken over the finance function somewhere and want to be sure nothing has been missed, a short review is usually enough.

Key takeaways

• Most expensive mistakes come from missing routines, not missing knowledge.
• Correct wrong entries; never delete and rewrite them.
• Setup errors repeat silently and need periodic verification.
• An expense without producible evidence will not survive an assessment.
• Report bad news early and with a proposed fix.