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Guide·Cybersecurity·3 min

Accounting firms: getting through tax season without incident

Three months when the firm cannot stop, temporary staff arrive and fraud attempts increase. What gets prepared beforehand, not during.

The essentials in 30 seconds

Tax season brings together three risks that add up: a workload that makes any interruption unbearable, temporary staff given access in a rush, and a season when bank transfer fraud attempts multiply. All three are dealt with ahead of time, through a temporary access procedure, a tested backup, and a bank verification rule with no exceptions.

An accounting firm spends part of the year at a pace where half a day of downtime is hard to make up. It is also the season when the most accounts are created in a rush, and when attention slips.

Temporary access, prepared in advance

Temporary staff who arrive on a Monday morning with three urgent files usually get broad access, because nobody has time to fine-tune it. That access then survives for several months.

  1. Prepare a standard profile before the season: rights strictly limited to the files assigned.
  2. Set an expiry date when the account is created, not afterwards. An account that closes on its own cannot be forgotten.
  3. Keep a list of temporary accounts, reviewed at the end of the period.
  4. Do not allow two staff members to share a session, even on a short assignment.

Transfer fraud, more active during the season

Attackers know the calendar. A message announcing a change of bank details at the height of the workload is far more likely to get through.

The rule is the same for every firm: always verify by phone, using a known number and never the one in the message, with no exception made for urgency. Urgency is precisely the attacker's tool.

What has to hold for three months

  • Remote access: staff working in the evening or at the weekend must be able to connect without makeshift fixes, with strengthened authentication.
  • The internet link: if the whole firm relies on hosted applications, an outage stops all activity. A second, independent link becomes a worthwhile investment if it avoids a single day of downtime.
  • Workstations: replacing a workstation mid-season takes days if no spare machine is ready. A machine prepared in advance costs less than a lost week.

The restore test happens beforehand

Restoring a client file in the middle of tax season is not something you want to discover or improvise. Run the test during the quiet period, and measure the actual time it takes.

While you are at it, check what the backup of your business software covers, and above all what it does not: working files stored locally by staff are almost always left out.

Frequently asked questions

How should a firm manage access for temporary staff?
By creating the account with an expiry date set from the start and rights limited to the files assigned. An account that deactivates automatically avoids a build-up of forgotten access, which is the main remaining risk after the season.
Why do fraud attempts increase during tax season?
Because the workload cuts the time spent on checks and makes an urgent request more credible. Attackers align with the known calendars of the professions they target.
Does an accounting firm need a second internet connection?
Yes, as soon as its business applications are hosted and the firm cannot work without a connection. The decision comes down to comparing the annual cost of the second link with the cost of a single day of downtime in the middle of tax season.

Next step

Prepare my firm before the season

Sources

Published 28 August 2026 · Équipe Skill Group, Conseil & pilotage

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