(B) procurement of construction materials, equipment or workers, as necessarily required for any works described in paragraphs (a) to (e);”. [28] The word “payment” is defined under s 4 CIPAA as “payment for work done or services rendered under the express terms of a construction contract;”. [29] The statements forming the basis of TUV’s claim against Intisari in the Payment Claim is as per paras 7, 8, 10, 11 and 12 above. There is obviously no written agreement or contract signed by both parties. [30] This led to the AIAC sending the letter dated 28.12.2021 to draw the attention of TUV’s solicitor to s 2 CIPAA and to AIAC CIPAA Circular 1B which provides that the CIPAA applies to every construction contract made in writing within the meaning of s 4, and under which a payment claim is made. AIAC requested the parties to revert with their confirmation that there is no contract in writing between the parties. [31] TUV’s solicitor replied to AIAC on the same day clarifying that – S/N fPXweJekGkiiSwO23auj6A “… it is not compulsory for a contract to be in writing for the matter to be put under the purview of CIPAA. It would be suffice so long there are written evidence and/ or documents proof for works done by the Claimant for the Respondent. For this purpose, we refer tor to Circular CIPAA 03 KLRCA's Guideline on the meaning of "Construction Contract Made In Writing" wherein the following definition of a 'construction contract in writing' has been adopted:- … Hence, it is the Claimant's position that there is a contract in writing as all the transactions of this matter is evinced in writing including but not limited to Invoices, Client Contract List for Equipment/Consumables, Daily Client Radiographic Film Approval Record, Weekly Timesheet, Quotations and payments made by Respondent to the Claimant for works done, which was attached together with our Payment Claim dated 4/10/2021.”. S/N fPXweJekGkiiSwO23auj6A There was no response from Intisari’s solicitor. [32] On 7.1.2022, AIAC again wrote to TUV’s solicitor to say, among others, as follows: “We stand by our AIAC Circular 03 dated 28th April 2014, but wish to highlight that the documents furnished to us by the Claimant towards establishing the existence of an agreement between the Parties are in fact, documents evincing the arrangement between the Respondent and third parties not named in the adjudication proceedings. Further, the invoices furnished to us issued by the Claimant to the Respondent, arises from an arrangement or a relationship that has not been documented in writing, as required under CIPAA. Moreover, by the Claimant’s own letter dated 7th December 2021, it has been indicated that “There is no main contract or supplemental agreement for all the works subcontracted by the Respondent to the Claimant. All works S/N fPXweJekGkiiSwO23auj6A are performed by the Claimant in accordance with the instructions given by the Respondent from time to time. As such, there is no fixed value of works”. It is for the above-mentioned reasons that we are conscious of the exclusions in CIPAA 2012 in proceeding with the registration of these adjudication proceedings. Notwithstanding this, and having already highlighted our concerns in proceeding with the above matter, if the Claimant is minded to proceed with the registration, we are content to leave this matter to the determination of the adjudicator when so appointed. For the avoidance of doubt, the Claimant is put on notice that its proceeding in this matter, including, vide any Request to the Director of the AIAC to appoint an adjudicator (Form 5) and continue thereafter, is strictly and solely at their own risk.”. [33] TUV’s solicitor replied to AlAC on 11.1.2022 to confirm TUV’s intention to proceed with registration of the claim and to leave to the Adjudicator, when so appointed, to determine on the issue of whether the claim falls S/N fPXweJekGkiiSwO23auj6A within the ambit of the CIPAA and/ or whether the Adjudicator has power to determine the claim. TUV’s solicitor additionally informed that it will present relevant documents to the Arbitrator to show the parties’ arrangement in writing. [34] Intisari finally broke the silence when it sent the letter dated 1.3.2022 to AIAC, referring to AIAC’s letter dated 7.1.2022 and AIAC CIPAA Circular 1A dated 11.11.2014 which – “… highlighted and emphasis strongly that the CIPAA 2012 applies to every construction contract made in writing within the meaning of Section 4 of the CIPAA. This matter is said to be binding upon AIAC as the issue has been well answered in the High Court of UDA HOLDINGS BHD V BISRAYA CONSTRUCTION SDN BHD and CAPITAL AVENUE DEVELOPMENT SDN BHD V BAUFR (M) SDN BHD. Hence, the following to the abovesaid Circular 1A abovesaid, we have been instructed by our client as follow: S/N fPXweJekGkiiSwO23auj6A a) That the Parties have not signed any formal and/or written agreement and/or contract with regard to the appointment of the Claimant as Subcontractor for the works at Aker Solutions; b) Following to the non-existence of such written agreement and/or contract between the Parties on the sub-contracting, the above matter is not suitable to be heard before the Adjudicator. c) As such, our client strictfully object that the abovesaid dispute to be heard via Adjudication under the AIAC. We are instructed by our client that our client reserve their rights under the law. …”. [35] Intisari’s current ground of challenge as properly understood involves the question as to whether the Adjudicator is clothed with jurisdiction S/N fPXweJekGkiiSwO23auj6A to enable him to adjudicate or to make a decision in respect of the dispute which was referred to him. Based on the types of jurisdictions as elucidated by the learned Judge in Terminal Perintis Sdn Bhd v Tan Ngee Hong Construction Sdn Bhd and another case [2017] MLJU 242 [see too, paras 16 and 17 in the judgment of View Esteem (supra)], the category of jurisdiction which comes into play is core jurisdiction. [36] It is well established that matters of jurisdiction, whether the total lack or excess of an adjudicator’s jurisdiction, may be raised before or after an adjudication decision has been made. It is immaterial that the complaint of lack or excess of jurisdiction was not raised during the adjudication proceeding. Even if the adjudicator makes a finding on his own jurisdiction, his decision is open to scrutiny by the court. This is because the adjudicator’s decision on his own jurisdiction is not binding and nor is it conclusive in any way (see Construction Adjudication In Malaysia, Third Edition, Sweet & Maxwell, 2022 by Lam Wai Loon and Ivan YF Loo at p 431 and the cases cited in the footnotes including Giatreka Sdn Bhd v SGW Engineering Construction Sdn Bhd (and Another Originating Summons) [2020] 1 AMR 193, Dekinjaya Builder Sdn Bhd v Chong Lek Engineering Works Sdn Bhd and another case S/N fPXweJekGkiiSwO23auj6A [2020] MLJU 2455, SS Builders Sdn Bhd v Darma Mekar Sdn Bhd [2020] MLJU 1147, EA Technique (M) Sdn Bhd v Malaysia Marine and Heavy Engineering Sdn Bhd and another case [2020] 11 MLJ 353 and Ahmad Zaki Sdn Bhd v Swaja Fascade Sdn Bhd & Anor [2019] MLJU 1224). [37] In this case, the Adjudicator had traced the events from the time that Intisari’s counsel wrote to the Adjudicator on 21.3.2022 (see paras 32 to 41 of the AD) stating, among others, the following: “… We refer also to the Adjudication Claim (Form 7) that have been received by our good office on 7th March 2022. Accordingly, as purported in Section 10 of CIPAA Act whereby the Respondent shall file an Adjudication Response (Form 8) responding to the said Adjudication Claim (Form 8) within 10 working days from the date of receipt of Adjudication Claim (Form 7). It is understood that thereof, the filing for S/N fPXweJekGkiiSwO23auj6A Adjudication Response (Form 8) would be on 21st March 2022. However, we have on 2nd March, 2022 sent an email dated 2nd March 2022 enclosing our letter dated 1st March, 2022 raising our client's objection regarding this Adjudication proceeding which until to date we have not received reply from your good office. Therefore, we humbly request that the filing of the said Adjudication Response be filed after we have received your good self's respond and/ or reply regarding our abovesaid request. …”. [38] The Adjudicator had called for a case management by Zoom hearing on 15.4.2022 whereby in the AD it was explained that – S/N fPXweJekGkiiSwO23auj6A “42. At the hearing, I canvassed Circular 3 of AIAC (then KLRCA, section 27(3) of CIPAA and the decision of Ravindran Paramaguru J (as he then was) in Innovatif Engineering (M) v Nomad Engineering Sdn Bhd 2017 AMR 722, where his Lordship adopted the view that “Construction contract in writing” ought to be given liberal meaning and should not be restricted to a formal contract.