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Did your attorney miss the deadline to file a counterclaim?

On Behalf of | Sep 1, 2026 | Duty of Care, Failure to Meet Deadlines, Fiduciary Duty, Investigation and Discovery, Lack of Due Diligence, Litigation Malpractice |

If someone has sued you, your defense attorney is responsible for protecting your rights throughout the proceedings. Part of that duty includes identifying whether you have any valid counterclaims against the party suing you.

If your attorney overlooked a counterclaim or didn’t file it in a timely fashion, you may be facing significant financial hardship. Unless your lawyer asserts the damages defensively later in the suit, you will have to pay damages to the party that sued you without being able to offset them with your own legitimate damages.

Your lawyer omitting a mandatory counterclaim could permanently shut the door on your recovery. Depending on the details of your case, this failure to assert a timely legal response could potentially constitute legal malpractice.

Understanding compulsory counterclaims and strict deadlines

In Florida’s civil courts, claims arising out of the same transaction or occurrence as the opposing party’s suit are known as compulsory counterclaims. In other words, if both parties have claims regarding the same transaction, those claims must generally be considered together.

A defense attorney must generally assert compulsory counterclaims when answering the lawsuit. (Certain pre-answer motions may adjust the timeline, and lawyers can sometimes add omitted counterclaims later by leave of the court.)

If a lawyer fails to plead a compulsory counterclaim by the initial deadline, that claim may be waived forever.

Florida courts do sometimes permit attorneys to add an omitted counterclaim upon showing oversight, inadvertence or excusable neglect. That said, it is up to the court to permit that, and there is no guarantee that it will.

Consider a practical scenario involving a commercial construction contract:

  • A general contractor sues a subcontractor for $100,000, claiming delayed completion of a project.
  • The subcontractor actually suffered $120,000 in damages because the general contractor provided defective building materials.
  • The subcontractor’s defense attorney files an answer to the suit but forgets to include a counterclaim for the defective materials.
  • The deadline to amend the pleadings passes and the court permanently denies the subcontractor’s $120,000 counterclaim.
  • The court ultimately orders the subcontractor to pay the general contractor $100,000.

Even if the defendant’s lawyer fails to file the counterclaim, he or she can assert transaction-related damages during the lawsuit as an affirmative defense under the doctrine of equitable recoupment to reduce or extinguish the judgment.

If this is not asserted or allowed, however, the subcontractor must pay the judgment in full.

Counterclaims follow strict rules

Attorneys owe their clients a duty of reasonable care established under Florida common law and contracts. Florida Rule of Civil Procedure 1.170(a) defines compulsory counterclaims, while Rule 1.170(f) specifically governs the process for adding omitted counterclaims by amendment.

Beyond common law and procedural rules, however, lawyers owe a fiduciary duty to preserve all viable avenues of relief. Failing to evaluate whether a client holds a compulsory counterclaim can constitute a breach of fiduciary duty.

Proving legal malpractice for a missed deadline

Demonstrating that an attorney committed malpractice requires more than just showing that they made a mistake. To establish a valid legal malpractice claim in Florida, an injured client must prove three essential elements:

  • Duty: The attorney owed a duty of care to represent the client competently.
  • Breach: The attorney breached that duty by failing to file the counterclaim within the required deadline.
  • Harm: The breach directly caused quantifiable financial harm.

Proving legal malpractice requires proving a case within a case. You have to show not only that the lawyer failed to file the timely counterclaim, but also that the counterclaim would have succeeded if it had been filed on time.

Get more information

If your former lawyer failed to file a timely counterclaim and you lost a financial remedy as a result, you may have legal options.

Speaking with an attorney who focuses on legal malpractice can help you understand whether your former counsel breached their professional duties and caused compensable financial damage.