                       PUBLISHED


UNITED STATES COURT OF APPEALS
             FOR THE FOURTH CIRCUIT


MARGARET GAYLE HERRING               
WARREN,
              Plaintiff-Appellant,
              v.                           No. 10-2105
SESSOMS & ROGERS, P.A.; LEE C.
ROGERS,
           Defendants-Appellees.
                                     

MARGARET GAYLE HERRING               
WARREN,
               Plaintiff-Appellee,
              v.                           No. 10-2155
SESSOMS & ROGERS, P.A.; LEE C.
ROGERS,
          Defendants-Appellants.
                                     
       Appeals from the United States District Court
   for the Eastern District of North Carolina, at Raleigh.
            Terrence W. Boyle, District Judge.
                    (7:09-cv-00159-BO)

                Argued: December 6, 2011

                Decided: January 11, 2012

 Before MOTZ, GREGORY, and FLOYD, Circuit Judges.
2               WARREN v. SESSOMS & ROGERS
Reversed and remanded by published opinion. Judge Motz
wrote the opinion, in which Judge Gregory and Judge Floyd
joined.


                         COUNSEL

ARGUED: Anthony J. Majestro, POWELL & MAJESTRO,
PLLC, Charleston, West Virginia, for Appellant/Cross-
Appellee. Dauna L. Bartley, ELLIS & WINTERS, LLP,
Raleigh, North Carolina, for Appellees/Cross-Appellants. ON
BRIEF: Angela Orso Martin, MARTIN ATTORNEY AT
LAW, PLLC, Sanford, North Carolina, for Appellant/Cross-
Appellee.


                         OPINION

DIANA GRIBBON MOTZ, Circuit Judge:

   Margaret Warren sued the law firm of Sessoms & Rogers,
P.A. ("S&R") and attorney Lee C. Rogers (collectively "the
defendants"), alleging that they violated the Fair Debt Collec-
tion Practices Act ("FDCPA" or the "Act"), 15 U.S.C. § 1692
et seq. Prior to any discovery, the defendants made Warren an
offer of judgment pursuant to Rule 68 of the Federal Rules of
Civil Procedure. When Warren did not accept the offer, the
defendants then moved to dismiss this action. They contended
that the offer of judgment mooted Warren’s case and, in the
alternative, that her complaint failed to state a claim upon
which relief could be granted. The district court dismissed
Warren’s complaint, concluding that her allegations failed to
"show a material violation" of the Act or that the defendants
"knowingly and willfully violated the Act." Warren appeals.
For the reasons set forth below, we reverse the judgment of
the district court and remand for further proceedings consis-
tent with this opinion.
                  WARREN v. SESSOMS & ROGERS                       3
                                 I.

  We first set forth the facts alleged in Warren’s amended
complaint.

   Shortly after Warren’s husband, Robert Warren, died in
March 2006, she learned of the debt at issue in this case: an
overdue personal VISA credit card account at Branch Bank-
ing & Trust Co. ("BB&T"). When Warren’s own attempts to
obtain the signature card on the account failed, she enlisted
the help of her son-in-law, Russ Gerald, to access the account
via online banking. Gerald discovered that the BB&T account
listed only Robert Warren’s name. However, at some point,
BB&T had begun sending Warren statements bearing both her
and her husband’s names. Under an assertedly mistaken belief
that she was obligated to make payments on the account after
her husband’s death, Warren had begun to make such payments.1
She eventually ceased these payments.

   In February 2009, Warren began to receive communica-
tions from S&R, a law firm "engaged in the collection of
debts," regarding the BB&T debt. S&R sent her an initial col-
lection letter dated February 24, 2009, which stated that
BB&T retained the firm "to assist them in the recovery of the
debt that you owe them." The letter informed Warren that she
was "in default under the terms of [her] credit agreement,"
and that the "entire balance [was] due and payable." Addition-
ally, the letter stated that Warren could "dispute this debt"
within thirty days of receipt of the letter. The letter advised
Warren that it was "an attempt to collect a debt" and that S&R
was a "debt collector." Defendant Rogers signed the letter on
behalf of S&R.

   Warren also alleges that she began to receive phone calls
from S&R in regard to the debt in February 2009. Specifi-
  1
   The debt has since been discharged in an unrelated bankruptcy pro-
ceeding.
4                  WARREN v. SESSOMS & ROGERS
cally, she alleges that S&R representative, John Harden, left
her the following telephone message: "Yes this call is for a
Mr. or Mrs. Warren. This is John Harden with Sessoms &
Rogers law firm. If you would, please give me a return call
as soon as possible." The message provided a call back num-
ber but did not identify S&R as a debt collector. At this time,
Warren "became afraid to answer her phone, her door or col-
lect the mail."

   Warren disputed the debt in a March 7, 2009 letter to S&R.
In the letter, she requested verification of the debt. Warren
also requested that S&R "[p]lease send all future correspon-
dence, including the verification [that she had] requested
directly to [her] attorney" and provided the name and mailing
address of her retained counsel. Thereafter, Rogers, on behalf
of S&R, sent another collection letter directly to Warren,
dated March 17, 2009. This letter began by thanking Warren
"for [her] recent letter concerning this account." Upon receipt
of this letter, Warren alleges that she "became highly upset,
angry, confused, irritated and worried."

   On November 16, 2009, Warren filed a one-count amended
complaint in federal district court, alleging numerous viola-
tions of the Act and seeking a jury trial.2 Specifically, and
most relevant to this appeal, she alleges that the defendants
violated 15 U.S.C. § 1692c(a)(2) by "communicating with
[her] when they knew she was represented by an attorney and
had actual knowledge of her attorney’s name and address"
and violated § 1692e(11) "by failing to notify [her] in subse-
quent communications that the communication was from a
debt collector." Warren also alleges several other violations of
§ 1692e based on her contention that S&R used "false, decep-
tive, or misleading representations or means in connection
with the collection of any debt." In her prayer for relief, War-
    2
   Although Warren alleged state law claims in an earlier complaint, she
abandoned those claims in her amended complaint.
                 WARREN v. SESSOMS & ROGERS                   5
ren seeks an award of unspecified actual damages, statutory
damages of $1,000, costs, and reasonable attorney’s fees.

   On December 4, 2009, the defendants filed an Offer of
Judgment pursuant to Federal Rule of Civil Procedure 68. The
offer provides for "judgment to be taken against" the defen-
dants for the following amounts:

    (1)   Actual damages in the amount of $250.00, or
          an amount determined by the Court upon Plain-
          tiff’s submission of affidavits or other evidence
          of actual damage;

    (2)   Statutory additional damages in the amount of
          $1,001.00;

    (3)   Costs of this action accrued to date; and

    (4)   A reasonable attorney’s fee to date as deter-
          mined by the Court.

In accordance with Rule 68, the offer provided Warren four-
teen days to accept these terms. Warren did not accept the
offer.

   Thereafter, on December 24, 2009, the defendants moved
to dismiss the amended complaint on two grounds. First, they
invoked Rule 12(b)(1), contending that Warren’s case had
"been mooted and must be dismissed for lack of subject mat-
ter jurisdiction" because they offered her, pursuant to Rule 68,
"all the relief to which" she was entitled. In the alternative,
the defendants invoked Rule 12(b)(6), arguing that the court
should dismiss Warren’s complaint because, since it "ade-
quately alleged only two minor technical violations," both of
which resulted from defendants’ "bona fide error," it failed to
state a claim upon which relief can be granted.

  Warren opposed the defendants’ motion to dismiss. She
maintained that the offer of judgment left "open the amount
6                WARREN v. SESSOMS & ROGERS
of actual damages" and "did not offer [her] all she may have
been entitled" including her "right to a jury trial for a determi-
nation of her actual damages." Warren further argued that the
defendants’ claim of "bona fide error" was an "affirmative
defense" for which they "bear[ ] the burden of pleading" and
proof "by a preponderance of the evidence," and thus pro-
vided no proper basis for dismissal under Rule 12(b)(6). War-
ren attached to her opposition memorandum her own affidavit
and those of her daughter and son-in-law attesting to the stress
that she endured from the defendants’ assertedly illegal debt-
collection efforts.

   The district court granted the defendants’ motion to dismiss
in a two-paragraph order, concluding Warren’s "allegations
do not show a material violation of [the] Act, nor that the
defendants knowingly and willfully violated the Act." Warren
timely noted this appeal.

                               II.

   Although the district court did not rule on the defendants’
Rule 12(b)(1) motion to dismiss on mootness grounds, we
must address this question at the outset, for if Warren’s case
is moot, we lack subject-matter jurisdiction. See Iron Arrow
Honor Soc’y v. Heckler, 464 U.S. 67, 70 (1983); S-1 v.
Spangler, 832 F.2d 294, 297 (4th Cir. 1987). This is so
because mootness principles derive from Article III of the
Constitution, which mandates that federal courts adjudicate
only disputes involving "a case or controversy." DeFunis v.
Odegaard, 416 U.S. 312, 316 (1974) (internal quotation omit-
ted). As a federal court, we must investigate the limits of our
subject-matter jurisdiction whenever that jurisdiction is "fairly
in doubt." See Ashcroft v. Iqbal, 129 S. Ct. 1937, 1945 (2009);
see also Arbaugh v. Y & H Corp., 546 U.S. 500, 514 (2006).

  A case becomes moot "when the issues presented are no
longer ‘live’ or the parties lack a legally cognizable interest
in the outcome." Simmons v. United Mortg. & Loan Inv.,
                 WARREN v. SESSOMS & ROGERS                     7
LLC, 634 F.3d 754, 763 (4th Cir. 2011) (internal quotation
omitted). A change in the law can render a case moot. Id. Or,
a change in factual circumstances can moot a case; for exam-
ple, "when the claimant receives the relief . . . she sought to
obtain through [her] claim," her case becomes moot. Id.
(quoting Friedman’s, Inc. v. Dunlap, 290 F.3d 191, 197 (4th
Cir. 2002)). Accordingly, we have found "there was no longer
any case or controversy" when "defendants had offered [a
plaintiff] the full amount of damages" to which the plaintiff
claimed entitlement. Zimmerman v. Bell, 800 F.2d 386, 390
(4th Cir. 1986).

   Thus, the initial question in this appeal is whether the
defendants’ Rule 68 offer of judgment mooted Warren’s case.
Rule 68 provides that, at least fourteen days before trial
begins, "a party defending against a claim may serve on an
opposing party an offer to allow judgment on specified terms,
with the costs then accrued." Fed. R. Civ. P. 68(a). If a plain-
tiff rejects a Rule 68 offer, she must "pay the costs incurred
after the offer was made" if the amount awarded at trial is less
than the offer. Fed. R. Civ. P. 68(d). The "plain purpose" of
this rule "is to encourage settlement and avoid litigation."
Marek v. Chesny, 473 U.S. 1, 5 (1985).

   To effectuate the purposes of Rule 68, an offer of judgment
"must specify a definite sum or other relief for which judg-
ment may be entered and must be unconditional." Simmons,
634 F.3d at 764 (citing 12 Charles Alan Wright, Arthur R.
Miller & Richard L. Marcus, Federal Practice and Procedure
§ 3002, p. 92 (2d ed. 1997)). "[T]he plaintiff must know
unequivocally what is being offered in order to be responsible
for refusing such offer." Id. When a Rule 68 offer unequivo-
cally offers a plaintiff all of the relief "she sought to obtain,"
Dunlap, 290 F.3d at 197, the offer renders the plaintiff’s
action moot. See, e.g., O’Brien v. Ed Donnelly Enters., Inc.,
575 F.3d 567, 575 (6th Cir. 2009); Rand v. Monsanto Co.,
926 F.2d 596, 597-98 (7th Cir. 1991); Abrams v. Interco, Inc.,
8                  WARREN v. SESSOMS & ROGERS
719 F.2d 23, 32-33 (2d Cir. 1983); see also Simmons, 634
F.3d at 763-64.

   The defendants contend that their Rule 68 offer provided
Warren with the maximum recovery available to her and thus
mooted her case. As Warren conceded at oral argument before
us, the Rule 68 offer of judgment did provide her with all pos-
sible statutory damages. The Act contemplates a maximum
recovery of $1,000 in statutory damages in "any action by an
individual," 15 U.S.C. § 1692k(a)(2)(A) (emphasis added),
and the offer of judgment provided for $1,001 in such damages.3

   The Act, however, places no similar statutory cap on a
plaintiff’s actual damages, see id. § 1692k(a)(1), and Warren
sought an unspecified award of actual damages in her
amended complaint. The defendants’ Rule 68 offer of judg-
ment proposed two alternative actual damage awards: (1)
$250, or (2) "an amount determined by the Court upon Plain-
tiff’s submission of affidavits or other evidence of actual
damage." The defendants contend that the offer of these
options moots Warren’s action.

                                   A.

   As to the first option, the defendants argue that Warren’s
"evidence fails to show" that she suffered more than $250 in
actual damages, and thus she has failed to prove that this
option did not fully satisfy her demand. Appellee’s Br. at 26.
Accordingly, they maintain, Warren has not proved the con-
tinued existence of a factual basis for subject matter jurisdic-
tion.

    Of course, it is true that when "a defendant challenges the
    3
   We further agree with the defendants that Warren "[can]not avert
mootness of the underlying action" simply because the offer of judgment
provided for costs and reasonable attorney’s fees "to date." See Spangler,
832 F.2d at 297 n.1.
                 WARREN v. SESSOMS & ROGERS                    9
existence of subject matter jurisdiction in fact, the plaintiff
bears the burden of proving the truth of such facts by a pre-
ponderance of the evidence." Vuyyuru v. Jadhav, 555 F.3d
337, 347 (4th Cir. 2009). As the defendants conceded at oral
argument, however, the district court engaged in no jurisdic-
tional fact finding in this case. The defendants would there-
fore have us make such factual findings in the first instance.
This we cannot do. See Columbus-Am. Discovery Grp. v. Atl.
Mut. Ins. Co., 56 F.3d 556, 575-76 (4th Cir. 1995) ("It is a
basic tenet of our legal system that, although appellate courts
often review facts found by a judge or jury to ensure that they
are not clearly erroneous, they do not make such findings in
the first instance.").

   Moreover, the defendants can point to no evidentiary
record from which any court could determine whether Warren
could satisfy this burden. The district court held no hearing to
resolve the jurisdictional issue nor has any discovery been
taken as to the amount of Warren’s actual damages. See Kerns
v. United States, 585 F.3d 187, 193 (4th Cir. 2009) (holding
that "when the defendant challenges the veracity of the facts
underpinning subject matter jurisdiction, the trial court may
go beyond the complaint, conduct evidentiary proceedings,
and resolve the disputed jurisdictional facts," and "when the
jurisdictional facts are inextricably intertwined with those
central to the merits, the court should resolve the relevant fac-
tual disputes only after appropriate discovery").

   Certainly, had Warren made a specific demand in the
amended complaint for actual damages and the defendants
offered that amount or more, the offer of judgment would
have mooted Warren’s action. See O’Brien, 575 F.3d at 573
(Rule 68 offer of judgment mooted two counts of plaintiff’s
complaint when defendants offered "the full amount of
claimed damages" for those counts). Similarly, had Warren
quantified her alleged damages in response to a discovery
request and the defendants offered that amount, her case
would be moot. See Rand, 926 F.2d at 597-98 (holding indi-
10               WARREN v. SESSOMS & ROGERS
vidual plaintiff’s case mooted by defendant’s offer for "the
full amount by which answers to interrogatories assert that
[the plaintiff] was injured, plus the costs of the suit" (empha-
sis added)); Zimmerman, 800 F.2d at 388 (same); see also
Abrams, 719 F.2d at 25-26 (holding Rule 68 offer of judg-
ment mooted case when plaintiffs acknowledged "the amount
offered was undoubtedly more than any damages they would
individually recover after trial").

   But, at this stage of the proceedings, before any evidentiary
hearing or judicial fact finding in the district court, we simply
cannot hold that Warren could not possibly recover more than
$250 if her case proceeded to a jury trial. See Sibersky v.
Borah, Goldstein, P.C., 242 F. Supp. 2d 273, 277-78
(S.D.N.Y. 2002) (explaining that, even though defendants
offered plaintiff full statutory damages, attorney’s fees, costs,
and additional $500 to settle FDCPA claim, the court could
not, on the basis of a Rule 12(b)(1) motion, determine the
existence or amount of actual damages). Accordingly, the first
option offered by defendants—payment of $250 in actual
damages—did not moot Warren’s case.

                               B.

   The second option offered by the defendants—conditioning
the amount of actual damages on the district court’s
determination—also failed to moot Warren’s action. To moot
a plaintiff’s case, an offer must be unequivocal. See Simmons,
634 F.3d at 766 (holding "conditional nature" of settlement
offer failed to "render the Plaintiffs’ . . . claims moot").

   We faced a similar issue last term in Simmons, in which a
defendant in a Fair Labor Standards Act case offered to settle
the litigation for an unspecified amount of damages. There,
the defendants offered to "fully" compensate plaintiffs "upon
receipt of an affidavit" that calculated the overtime pay at
issue and "a statement explaining how the calculation of over-
time amounts claimed was done." Id. at 760-61. Judge Hamil-
                  WARREN v. SESSOMS & ROGERS                       11
ton carefully explained for the court that the "vagaries
inherent in [the] offer of settlement" raised questions about
what might result if the defendant challenged the plaintiffs’
explanation of its damages calculation. Id. at 766.

   The offer here, leaving the "amount [of damages to be]
determined by the Court upon plaintiff’s submission[s]," suf-
fers from the same inherent flaw. Defendants’ offer was not
unequivocal but "conditional," predicated on what the district
court as fact finder might or might not do. See id.; see also
Basha v. Mitsubishi Motor Credit of Am., Inc., 336 F.3d 451,
454–55 (5th Cir. 2003) (describing as "vague" Rule 68 offer
in FDCPA case that left calculation of actual damages to later
agreement by attorneys). Further, like the offer in Simmons,
this option provided Warren no guarantee that the defendants
would not offer their own submissions as to damages or chal-
lenge the veracity of hers.4

   Moreover, the defendants’ offer deprives Warren of her
right to have a jury determine disputes of fact regarding actual
damages. The defendants have acknowledged, as they must,
that Warren was entitled to have a jury determine her actual,
as opposed to statutory, damages. See Fed. R. Civ. P. 38 (pre-
serving the "right of trial by jury" in civil actions); 15 U.S.C.
§ 1692k(a)(1), (2)(A) (providing for actual and statutory dam-
ages and limiting a court’s discretion to awarding only the
statutory damages). Yet, as the defendants would have it, a
savvy defendant in an FDCPA case could avoid submitting
the contested issue of actual damages to a jury by offering to
substitute the district court as fact finder.

   The defendants contend that their offer permitted a jury
trial on actual damages because the district court could have
  4
    We reject the defendants’ argument that Warren’s failure to make a
settlement demand is to blame for the ambiguity of the offer because
"such [a] complaint matters not to a mootness inquiry." Simmons, 634
F.3d at 766.
12               WARREN v. SESSOMS & ROGERS
impaneled a jury for that purpose. See Fed. R. Civ. P. 39(b)
(providing that a "court may, on motion, order a jury trial on
any issue for which a jury might have been demanded").
However, such relief would still be conditioned on what the
district court in its discretion might or might not do. Simmons,
634 F.3d at 766. Again, an offer must be unequivocal to moot
a plaintiff’s case.

  In sum, neither option offered by defendants to satisfy War-
ren’s alleged actual damages moots her case.

                              III.

   Having determined that the defendants’ Rule 68 offer of
judgment did not moot Warren’s action, we turn to the ques-
tion of whether the district court properly dismissed Warren’s
complaint pursuant to Rule 12(b)(6). We review the district
court’s grant of a motion to dismiss de novo, accepting as true
the complaint’s factual allegations and drawing all reasonable
inferences in favor of the plaintiff. See E.I. du Pont de
Nemours & Co. v. Kolon Indus., Inc., 637 F.3d 435, 440 (4th
Cir. 2011).

   As the Supreme Court recently explained, "Congress
enacted the FDCPA in 1977 to eliminate abusive debt collec-
tion practices, to ensure that debt collectors who abstain from
such practices are not competitively disadvantaged, and to
promote consistent state action to protect consumers." Jerman
v. Carlisle, McNellie, Rini, Kramer & Ulrich LPA, 130 S. Ct.
1605, 1608 (2010) (internal citation omitted); see also 15
U.S.C. § 1692(e). In this appeal, Warren challenges the dis-
trict court’s dismissal of her FDCPA claim as it pertains to the
defendants’ alleged violations of 15 U.S.C. §§ 1692e(11) and
1692c(a)(2), and further maintains the district court erred in
holding that she had to allege the defendants "willfully" vio-
lated the Act.
                 WARREN v. SESSOMS & ROGERS                  13
                              A.

   First, Warren contends that the district court erred in mak-
ing a blanket holding that she failed to allege a "material vio-
lation of" the Act in relation to her allegations under 15
U.S.C. § 1692e(11). That subsection requires debt collectors
"to disclose" in their initial and subsequent communications
with consumers "that the communication is from a debt col-
lector." Id. Warren maintains that the February 2009 phone
call violated § 1692e(11).

   Generally, § 1692e prohibits debt collectors from using
"any false, deceptive, or misleading representation or means
in connection with the collection of any debt." Section 1692e
also provides a non-exhaustive list of "conduct" that satisfies
this general prohibition. With one exception, that list involves
particular types of false or misleading representations from
the debt collector. Only the subsection relied on by Warren,
§ 1692e(11), contemplates a "failure to disclose" certain
information, namely "that the communication is from a debt
collector."

   Although Congress did not expressly require that any viola-
tion of § 1692e be material, courts have generally held that
violations grounded in "false representations" must rest on
material misrepresentations. For example, analyzing an
alleged violation of § 1692e(2), which prohibits a "false rep-
resentation of the character, amount, or legal status of any
debt," the Seventh Circuit reasoned that the Act "is designed
to provide information that helps consumers to choose intelli-
gently," and thus held that because "[a] statement cannot mis-
lead unless it is material, . . . a false but non-material
statement is not actionable." Hahn v. Triumph P’ships LLC,
557 F.3d 755, 757-58 (7th Cir. 2009); see also Donohue v.
Quick Collect, Inc., 592 F.3d 1027, 1033 (9th Cir. 2010); Mil-
ler v. Javitch, Block & Rathbone, 561 F.3d 588, 596 (6th Cir.
2009).
14               WARREN v. SESSOMS & ROGERS
   Warren’s allegations, however, do not involve a false rep-
resentation, or any affirmative representation for that matter.
Rather, as described above, Warren complains about conduct
that involves a "failure to disclose" "that the communication,"
the February 2009 phone message, was "from a debt collec-
tor." The statute expressly prohibits this exact omission by
requiring debt collectors to disclose their status in every com-
munication with a consumer. Accordingly, whether a materi-
ality requirement attaches to other violations of § 1692e has
no impact on Warren’s allegations that the defendants vio-
lated § 1692e(11). Cf. Sayyed v. Wolpoff & Abramson, 485
F.3d 226, 235-36 (4th Cir. 2007) (analyzing alleged
§ 1692e(11) violation with no discussion of materiality
requirement). The district court thus erred in concluding that
Warren failed to allege a violation of § 1692e(11).

                              B.

   Warren also contends that the district court erroneously
held that she failed to allege that the defendants "knowingly"
violated § 1692c(a)(2) of the Act. Section 1692c(a)(2) prohib-
its a debt collector from "communicat[ing] with a consumer
in connection with the collection of any debt . . . if the debt
collector knows the consumer is represented by an attorney
with respect to such debt and has knowledge of, or can readily
ascertain, such attorney’s name and address."

   Here, Warren alleges that by letter dated March 7, 2009,
she informed the defendants that an attorney represented her,
directed the defendants to communicate with her attorney, and
provided the defendants with her attorney’s name and mailing
address. Nevertheless, a week later on March 17, 2009, the
defendants sent directly to Warren another letter in connection
with the collection of the debt at issue. The letter opened with
the phrase, "Thank you for your recent letter concerning this
account." Drawing all reasonable inferences in favor of War-
ren, her allegations adequately state that the defendants, hav-
ing received Warren’s letter, knew she was "represented by an
                 WARREN v. SESSOMS & ROGERS                  15
attorney" and how to contact the attorney when they sent her
the March 17 letter. And yet, in violation of § 1692c(a)(2), the
defendants communicated not with her attorney, but directly
with her. Thus, we can only conclude that the district court
erred in concluding Warren failed to allege that the defen-
dants violated § 1692c(a)(2).

                              C.

   Finally, Warren contends that the district court erred by
requiring her to allege that the defendants "willfully" violated
the Act. The statute itself contains no scienter requirement.
Rather, it imposes liability on "any debt collector who fails to
comply with any provision" of the Act. 15 U.S.C. § 1692k(a);
see also id. § 1692k(b) (directing courts to consider whether
the "debt collector’s noncompliance was intentional" in
assessing "the amount of liability" (emphasis added)). In other
words, as a number of our sister circuits have held, the
FDCPA "imposes liability without proof of an intentional vio-
lation." See Allen ex rel. Martin v. LaSalle Bank, N.A., 629
F.3d 364, 368 (3d Cir. 2011); LeBlanc v. Unifund CCR Part-
ners, 601 F.3d 1185, 1190 (11th Cir. 2010); Donohue, 592
F.3d at 1030; Ellis v. Solomon & Solomon, P.C., 591 F.3d
130, 135 (2d Cir. 2010); Ruth v. Triumph P’ships, 577 F.3d
790, 805 (7th Cir. 2009).

   The Act does contain an affirmative defense, however.
Under 15 U.S.C. § 1692k(c), a debt collector can escape lia-
bility if it "shows by a preponderance of evidence that the vio-
lation was not intentional and resulted from a bona fide error
notwithstanding the maintenance of procedures reasonably
adapted to avoid any such error." Such a "bona fide error"
defense is one that a defendant must prove. See Johnson v.
Riddle, 305 F.3d 1107, 1121 (10th Cir. 2002) (holding that
defendant "carries the burden of proving" the "affirmative
defense"); see also Sayyed, 485 F.3d at 232 (describing
§ 1692k(c) as "offer[ing] a kind of qualified immunity to debt
collectors"). Certainly, the defendants in this case will have
16                  WARREN v. SESSOMS & ROGERS
the opportunity to do so on remand. However, the district
court turned the defense on its head in this case, requiring the
plaintiff to plead and prove that the defendants acted willfully.
By doing so, the district court erred.

                                   IV.

   For the foregoing reasons, we hold that the defendants’
offer of judgment did not moot the case and that the district
court erred in concluding that Warren’s amended complaint
failed to allege violations of 15 U.S.C. §§ 1692c(a)(2) and
1692e(11). Thus, we reverse the judgment of the district court
and remand for further proceedings.5

                                    REVERSED AND REMANDED




  5
    In a cross-appeal, the defendants have challenged the district court’s
dismissal of their motion for sanctions against Warren’s attorney. The dis-
trict court dismissed the motion as moot in light of its dismissal of War-
ren’s complaint. Warren agrees that we should reverse and remand the
dismissal of the sanctions motion if she prevails in her appeal. Accord-
ingly, we also reverse and remand the district court’s dismissal of the
defendants’ motion for sanctions.
