Cabling at 3%, supply at 5%: a fibre network’s price revision has no single threshold

The specification for a fibre backbone between two exchanges carries a single price-revision line: it applies above 5% of the amount, at 80% of the excess. Twelve months after the award, energy prices for excavation plant and copper prices in the cable conductors rise together. The contractor claims the revision; the RUP finds that single line has not been the law since late 2024. The contract is at once trenching and ducting — works — and cable, active equipment — supply. Since article 60 of Legislative Decree 36/2023 was rewritten, the two components carry different thresholds, different percentages, different indices. The specification had written only one.

Two thresholds, not one

Paragraph 1 of article 60 requires: «Nei documenti di gara iniziali delle procedure di affidamento è obbligatorio l’inserimento delle clausole di revisione prezzi riferite alle prestazioni oggetto del contratto» (price-revision clauses tied to the contract’s own services are compulsory in the initial tender documents). Not an option: an obligation from the tender notice on.

Until 30 December 2024, paragraph 2 treated works, supplies and services alike: one threshold, 5% of the amount, one percentage, 80% «della variazione stessa» (of the change itself) — the whole change, not merely the part exceeding the threshold. From 31 December 2024 — under Legislative Decree 31 December 2024, no. 209, the Code’s amending decree, which rewrote paragraph 2 and added paragraph 2-bis — the threshold split: for works it triggers above a «variazione del costo dell’opera […] superiore al 3 per cento dell’importo complessivo» (a works-cost change […] exceeding 3 per cent of the total amount) and applies «nella misura del 90 per cento del valore eccedente» (at 90 per cent of the excess value); for supplies or services it triggers above 5% and applies at 80% of the excess. Paragraph 2-bis adds an option for services and supplies only: «meccanismi ordinari di adeguamento del prezzo del contratto all’indice inflattivo convenzionalmente individuato tra le parti» (ordinary mechanisms indexing the contract price to an agreed inflation measure), whose increase stays out of the 5% threshold calculation.

Two indices, produced by two different parties

Paragraph 3 splits the indices too: for works, «gli indici sintetici individuati ai sensi del comma 4-quater» (the synthetic indices identified under paragraph 4-quater); for services and supplies, ISTAT’s consumer, production and contractual-wage indices. Paragraph 4-quater points to Annex II.2-bis of the Code, introduced by the same amending decree: its article 1, paragraph 4, sets the rule for a contract like this one — «In caso di contratti misti, si applicano, alla componente di lavori, le disposizioni di cui alla Sezione II del presente Allegato e, alla componente di forniture e servizi, le disposizioni di cui alla Sezione III» (for mixed contracts, works follow Section II of this Annex, supplies and services follow Section III). Two sections, not one average across both.

For works, the Annex (art. 4) hands the choice to the designer: at the design stage behind the tender, they identify, among twenty homogeneous work categories (TOL) listed in Table A, the ones relevant to trenching and cabling, weigh their share of the amount, and build a project-specific synthetic index. That index, though, exists only once the Ministry of Infrastructure and Transport has published it: paragraph 4 of article 60 leaves it to a decree of the Ministry of Infrastructure and Transport, adopted after consulting ISTAT. Until that decree, the Annex (art. 16) keeps the previous regime alive, with the old ISTAT indices «nel testo vigente alla data del 1° luglio 2023» (in the text in force on 1 July 2023) — and a footnote to the same article warns that only three had been published, for residential buildings, industrial sheds and tunnelled road sections: none for a network trench. The decree arrived on 30 March 2026 — MIT executive decree no. 743, adopting the ISTAT cost indices for the homogeneous work types of Table A — which «acquista efficacia il giorno stesso della sua pubblicazione» (takes effect the day it is published) on the Ministry’s site, dated by the Ministry 28 April 2026. Before that date, a fibre-laying tender already under way stayed, for its works component, on the three old indices: none of which covered it.

For the supply side — cable, active equipment — the Annex (arts. 10-11) leaves the choice to the contracting authority: it identifies the service’s CPV code and, through Table D, matches it to the relevant ISTAT index or a weighted system of several; if the CPV is not listed, it chooses the index «ritenuto maggiormente pertinente all’attività oggetto dell’appalto» (deemed most relevant to the contract’s activity). Here the data point is never missing: what is missing is only someone taking responsibility for it before the tender goes out.

Once written, the clauses activate on their own: the Annex (art. 3) triggers them «automaticamente dalla stazione appaltante, anche in assenza di istanza di parte» (automatically by the contracting authority, without either party’s request), once the threshold is crossed — not on the contractor’s claim.

What to write in the specification

Separate the works component from the supply component, line by line: trenching, ducting and cabling on one side; cable, active equipment and materials on the other — with their respective thresholds, 3%/90% and 5%/80%.
Have the designer state, at the design stage, which TOL apply to the trenching and cabling and their weight, citing MIT executive decree no. 743 of 30 March 2026 as the source of the indices.
Have the CPV code for cable and equipment stated, with the ISTAT index or weighted system from Table D — not a generic nod to ISTAT indices with no table number.
State whether the paragraph 2-bis ordinary adjustment mechanism is added for the supply side, and how its increase stays out of the 5% threshold calculation.
Fix the monitoring frequency for the indices in the initial tender documents: activation is automatic, but only if someone has stated how often it is checked.

How it is checked at acceptance

The works manager assesses the change in the synthetic index and forwards it to the RUP with the revisional progress statement; for supplies, the contracting authority checks the change in the CPV index and communicates the revised prices. A specification that just says price revision at 5% without saying which part is works and which is supply leaves the works manager to find out at closeout — once the wrong threshold has already been applied.

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What we haven’t verified

We have not verified whether one of the TOL in MIT decree no. 743/2026 explicitly covers trenching and ducting for telecommunications, or whether the designer must fit it under a more generic heading: Table A is published as a graphic, not as extractable rows. We have not verified whether any ANAC ruling classifies splicing and testing as works or as a service for threshold purposes. The MIT page announcing the decree calls it, in its own text, «Decreto Dirigenziale n. 730/2026», and links to it under that number; the document itself carries in its digital signature the protocol m_inf.AAAB044.REG_DECRETI.R.0000743.30-03-2026, and the number is 743: we report this as a discrepancy in the source, not our own transcription error.

The point

A fibre network contract is not works with a supply attached: it is two contracts under one tender, with two thresholds, two percentages and two indices that neither party — designer nor contracting authority — holds for the other. A specification that does not say so leaves the question open until the first price rise, when it is too late to answer calmly. It is the same principle behind a specifications-compliance service built together with optical network design: the threshold is declared before the tender, not discovered at testing. Subcontracted cabling, for that matter, inherits the same clause — we wrote about who may carry out the work in a network contract for the telecom sector.

Are you drafting a mixed specification and unsure how to split the thresholds between works and supply, or facing a price revision worked out with the wrong index? Talk to an engineer: the site visit is free, and the two thresholds get written before the tender, not negotiated at the first price rise.