SecProbe.io

CORRESP
 1
 filename1.htm

 September 9, 2025

 VIA EDGAR

 U.S. Securities and Exchange
Commission

 Division of Corporation
Finance

 100 F. Street, N.E.

 Washington, D.C. 20549

 Attn:
 Yolanda
 Guobadia

 Robert
 Babula

 Re:
 CDT
 Environmental Technology Investment Holdings Limited

 Form
 20-F for the Fiscal Year ended December 31, 2024

 Filed
 May 15, 2025

 File
 No. 001-42007

 Ladies and Gentlemen:

 CDT Environmental Technology Investment
Holdings Limited (the " Company ") hereby provides the following information in response to the comments received from
the staff (the " Staff ") of the U.S. Securities and Exchange Commission (the " Commission ") on July
29, 2025 with respect to the above-referenced filing. The Company is filing Amendment No. 1 to the Form 20-F for the fiscal
year ended December 31, 2024 (the " Amended 2024 Form 20-F ") to respond to comments 1 and 4 received from
the Staff. For ease of the Staff's review of the response letter, the Company's responses to comments 2 and 3 are repeated
from the response letter previously submitted to the Staff on August 26, 2025.

 All page number references contained
in the Company's response below correspond to the page numbers in the Annual Report. Any capitalized terms used herein but not defined
herein shall have the meanings given to them in the Annual Report.

 Form 20-F for the Fiscal Year ended December
31, 2024

 Financial Statements

 Report of Independent Registered Public Accounting
Firm, page F-2

 1.
 We note that the audit report on page F-2 indicates the audits were conducted in accordance with the standards of the PCAOB though also in accordance with auditing standards generally accepted in the United States of America.

 Please discuss this language with Enrome
LLP, as the reference to auditing standards generally accepted in the United States of America is no longer appropriate or necessary.
This was addressed in our Commission Guidance Regarding the Public Company Accounting Oversight Board's Auditing and Related Professional
Practice Standard No. 1 (Release Nos. 33-8422; 34-49708; FR-73), effective May 14, 2004.

 Please obtain and file a revised audit
opinion from the auditor that adheres to the guidance in PCAOB Auditing Standard 3101, including paragraph 09(c).

 Company Response : The Company acknowledges the Staff's comment and respectfully advises
the Staff that a revised audit opinion with the inadvertent reference to auditing standards generally accepted in the United States of
America removed has been filed with the Amended 2024 Form
20-F.

 Note 4 - Accounts receivable, net, page F-21

 2.
 We note your comparison of "days sales outstanding" on page 68, indicating an increase to 455 for 2024, from 262 in 2023, and details regarding the allowance for credit losses on page F-11, indicating an increase to $9.3 million at the end of 2024 from about $3.0 million a year earlier. We also note that your allowance is about 31% of 2024 revenues of $29.8 million, and that you have disclosure on page 67 explaining that a $23.1 million increase in accounts receivable during 2024 was "primarily due to a longer collection cycle" which you attribute to "delays in the government billing approval process" resulting from economic downturn in the PRC.

 Please provide us with further details
regarding the activity reflected in the accounts receivable balance reported on page F-3, showing an increase of 55% compared to the end
of the prior year, and resulting in a balance that is 152% of total revenues for the year. For example, clarify the extent of any material
concentrations related to specific customers or groups of customers and describe any irregularity in the pattern of accumulating balances
over the course of the year. Also provide us with an accounts receivable aging schedule as of December 31, 2024, delineated between the
government and non-government customers.

 Company Response : The Company respectfully
acknowledges the Staff's comment and provides the following explanation. The 55% increase in accounts receivable as of December
31, 2024, compared to the prior year, was primarily attributable to progress billings on sewage treatment system projects. As noted, revenues
from these projects are recognized over time using the input method (cost-to-cost measure of progress), while accounts receivable are
recorded when the billing milestones are met, and the Company has an unconditional right to payment. Accordingly, the increase in accounts
receivable reflects the billing activity under contractual terms rather than increase in revenue.

 The increase in accounts receivable was primarily
attributable to balances from the following six customers as of December 31, 2024 with balances over 5% of our total accounts receivables.
Delays in collection were mainly the result of administrative processing by the local government; however, the Company continues to work
diligently with the relevant authorities to facilitate timely collection. The Company has also provided below the details of amounts collected
to date, the status of remaining balances, and management's expectations regarding their collectability of these six customers.
Exhibit 1 attached to this response letter contains an accounts receivable aging schedule as of December 31, 2024, delineated between
the government and non-government customers and categorized by aging buckets.

 ●
 Long
 Yuan Construction Group Co., Ltd ("Long Yuan")

 The
accounts receivable balance from Long Yuan, a government affiliated customer, was approximately $13.6 million and $4.0 million as of
December 31, 2024 and 2023, representing 25.0% and 12.3% of total accounts receivable, respectively. The related revenue was derived
from Project Lianjiang. As of August 25, 2025, the Company had collected approximately $0.7 million of the December 31, 2024 balance
from Long Yuan and expects to collect the remaining balance by December 2026.

 ●
 Shenzhen
 Bell Eco-environment Technology Co., Ltd ("Bell")

 The
accounts receivable balance from Bell, a government affiliated customer, was approximately $8.9 million and $2.5 million as of December
31, 2024 and 2023, representing 16.3% and 7.8% of total accounts receivable, respectively. The related revenue was derived from Project
Zhongshan. As of August 25, 2025, the Company had collected approximately $0.56 million of the December 31, 2024 balance from Bell and
expects to collect the remaining balance by December 2026.

 ●
 Fujian
 Provincial Construction Research & Engineering Consulting Co., Ltd ("Fujian")

 The
accounts receivable balance from Fujian, a government affiliated customer, was approximately $7.8 million and $0.5 million as of December
31, 2024 and 2023, representing 14.3% and 1.7% of total accounts receivable, respectively. The related revenue was derived from Project
Jianyang. As of August 25, 2025, the Company had collected approximately $1.0 million of the December 31, 2024 balance from Fujian and
expects to collect the remaining balance by December 2026.

 ●
 China
 Construction Eighth Engineering Division Corp., Ltd. ("China Construction")

 The
accounts receivable balance from China Construction, a government affiliated customer, was approximately $7.1 million and $2.4 million
as of December 31, 2024 and 2023, representing 13.1% and 7.4% of total accounts receivable, respectively. The related revenue was derived
from Project Wuyishan. As of August 25, 2025, the Company had collected approximately $0.2 million of the December 31, 2024 balance from
China Construction and expects to collect the remaining balance by December 2026.

 ●
 CCCC
 SHANGHAI DREDGING CO., LTD. ("CCCC Shanghai")

 The
accounts receivable balance from CCCC Shanghai, a government affiliated customer, was approximately $4.8 million and $2.7 million as
of December 31, 2024 and 2023, representing 8.8% and 8.4% of total accounts receivable, respectively. The related revenue was derived
from Project Guankou. As of August 25, 2025, the Company had collected approximately $0.7 million of the December 31, 2024 balance from
CCCC Shanghai and expects to collect the remaining balance by June 2026.

 ●
 Guangdong
 Wange Construction Engineering Co., Ltd. ("Guangdong Wange")

 The accounts receivable balance from Guangdong
Wange, a government affiliated customer, was approximately $4.6 million and $0 as of December 31, 2024 and 2023, representing 8.4% and
0% of total accounts receivable, respectively. The related revenue was derived from two Project- Xinjiang and Sichuan Anya. As of August
25, 2025, the Company had collected approximately $0.7 million of the December 31, 2024 balance from Guangdong Wange and expects to collect
the remaining balance by November 2026.

 As of August 25, 2025, the Company had collected
an aggregate total of approximately $4.92 million of the accounts receivable balance outstanding as of December 31, 2024. Of this amount,
approximately $3.86 million was collected from the six customers discussed above, while the remaining approximately $1.06 million was
collected from various smaller customers. The Company has engaged in intensive communications with its local government customers regarding
the collection process. During these discussions, customers have indicated that the government began implementing measures to address
local government debt issues at the beginning of this year and have committed to improved payment schedules going forward with specific
payment plans provided to the Company.

 The improvement in collections is reflected
in our recent performance. While the Company collected approximately $1.9 million during the first half of 2025 (January through June),
collections accelerated significantly to approximately $3.0 million during July and August 25, 2025, demonstrating the effectiveness of
the government's debt resolution initiatives and validating our customers' payment commitments.

 Based on these intensive communications,
the demonstrated improvement in collection patterns, and the specific payment schedules provided by our customers, the Company believes
the customer payment plans are credible and expects to collect the remaining balance of the December 31, 2024 accounts receivable on or
before December 31, 2026.

 Please explain to us how you applied FASB
ASC 606-10, subparagraphs 25-1(e), 55- 3A through 55-3C, and 25-5 through 25-7, in assessing the probability that you would collect substantially
all of the consideration to which you were entitled under the contracts with customers, in determining that all criteria for initial
recognition had been met, and if this can be shown, also explain how you considered the delays in collection in concluding that year-end
balances were recoverable.

 Company Response : In connection with
Staff's comment regarding how the Company applied ASC 606-10-25-1(e), 55-3A through 55-3C, and 25-5 through 25-7 in assessing the
probability that the Company would collect substantially all of the consideration to which the Company was entitled under the contracts
with customers, the Company provides the following explanation.

 ●
 Assessment of Collectability (ASC 606-10-25-1(e) and 55-3A through 55-3C)

At inception, the Company evaluated whether it was probable that it would collect substantially all of the consideration to which it would
be entitled in exchange for the goods and services to be transferred. Consistent with ASC 606-10-55-3A through 55-3C, this assessment
was partly forward-looking and considered the ability and intention of the customers to pay. The Company concluded that this criterion
was met mainly due to the following:

 o
 The
 customers are government-affiliated entities with strong financial capacity;

 o
 Contractual
 payment terms are milestone-based, which is based on the progress of the construction, which reduces exposure to credit risk; and

 o
 The
 Company retains customary rights to withhold further performance until payments are received.

 ●
 Reassessment
 Considerations (ASC 606-10-25-5 through 25-7)

 In accordance with ASC 606-10-25-5, the
Company does not reassess the contract criteria unless there is a significant change in facts and circumstances, such as a deterioration
in a customer's ability to pay. The Company has not identified any such significant change. Rather, delays in payment are primarily
due to administrative processing common in government contracts, not to a change in customers' ability or intention to pay.

 ASC 606-10-25-6 and 25-7 address situations
in which a contract does not meet the 25-1 criteria at inception. Since the Company determined that all criteria, including collectability,
were satisfied at contract inception, these provisions are not applicable.

 3.
 We note your disclosure on page 69 regarding the aging method applied in determining your allowance for doubtful accounts, explaining that you apply "incremental ratios" of 15%, 25%, and 100% of accounts having outstanding balances aged between 270 days and one year, one year and two years, and beyond two years, respectively. Please explain to us how you developed these default rates and clarify whether the policy is uniformly applied to all customer classes and, if this is the case, also explain to us how you assessed the credit risk profiles of the various customer groups in determining that a uniform rate for all customers would be appropriate.

 Company Response : The Company respectfully
advises the Staff that the baseline default rates of 15% for receivables aged between 270 days and one year, 25% for receivables aged
between one and two years, and 100% for receivables older than two years were determined based on prior-period historical collection performance
in those specific aging categories.

 Then, the Company reevaluated the allowance
under the CECL model by calculating an Expected Credit Loss ("ECL") in accordance with ASC 326. This calculation incorporates
factors such as current economic trends, specific geographic conditions, and known delays inherent in governmental billing processes.
The Company then compares the baseline aging-rate allowance to this calculated ECL. If the ECL estimate exceeds the baseline, the Company
records higher amount; if it is lower, the baseline rate is retained as a more conservative approach.

 Applying the aging-method baseline across
the receivables resulted in a total allowance of approximately $6.9 million as of December 31, 2024. However, upon applying the full CECL
analysis with ECL which included consideration of collection history, current economic trends, specific geographic conditions, and known
delays inherent in governmental billing processes, the estimated expected loss increased to $9.3 million. Therefore, the Company recorded
the full $9.3 million allowance for its accounts receivable in accordance with the methodology presented above.

 Given that over 90% of both revenues and
accounts receivable as of December 31, 2024 and 2023 relate to government-affiliated customers and these receivables are subject to uniform
administrative and billing infrastructure, management determined the credit risk profile across customer groups is sufficiently homogeneous
to justify applying a uniform baseline rate across government affiliate customers with adjustment based on assessment of CECL model. Non-government
customers are immaterial as compared to our total accounts receivable balance and are included in the same pooling and subject to the
same ECL methodology based on prior-period historical collection performance.

 Exhibits

 4.
 We note that you list certifications for Exhibits 12.1, 12.2, 13.1 and 13.2 and indicate these were furnished with the report, although this does not appear to be the case. Please amend your filing to include the certifications prescribed in paragraphs 12 and 13 of the Instructions As To Exhibits for Item 19 of Form 20-F. Please ensure that the certifications refer to the appropriate fil