How to read your bill

To make it easier to read your bill, we've provided a glossary with the terms we use to indicate costs and services. Click on the letters and start searching!

You can also download the glossary in PDF format.

Actual consumption in the period

This is the water consumption in cubic metres relative to the period elapsed between two meter readings. It is therefore equal to the difference between the numbers indicated by the meter at the last reading detected (or the last self-reporting) and the numbers indicated by the meter at the previous reading detected (or the previous self-reporting).

Italian Regulatory Authority for Energy, Networks and the Environment

This is an independent administrative authority, established by Italian Law no. 481 of 14 November 1995, which has the task of protecting the interests of consumers, promoting knowledge, efficiency and the dissemination of services throughout the country. Since 2012, ARERA has been assigned the functions related to the regulation and control of water services.


The aqueduct services are used to withdraw water from the source, make it potable and feed it into the water mains for distribution to users. The fee for the service consists of a fixed component, independent of consumption, and a variable component (€/m3) depending on the cubic metres consumed and differentiated by consumption levels.

Villoresi reclamation contribution

This is the contribution that, if due pursuant to Regional Law 31/2008 art. 90. para. 7, is debited in the bill and subsequently credited to the Est Ticino Villoresi Reclamation Consortium. As required by current legislation, the amount serves to finance the Consortium's activities, i.e., the distribution and management of water resources for irrigation purposes, participation in environmental protection and hydraulic system monitoring, including the supply of underground groundwater. For more information, visit the website

Average daily consumption

This is equal to the average annual consumption (CA) divided by 365 days and is used to calculate the estimated consumption in case of invoicing on account.

Average annual consumption (CA)

This is the consumption in cubic metres calculated on the basis of the consumption recorded between two actual detected readings, in a period of not less than 300 calendar days and taking into account the change in annual consumption over the last three years (if available). The CA shall be updated annually with effect from 1 January. In the absence of detected measurement data, the CA will be equal to the average value per similar user type (art. 10 ARERA Resolution no. 218/2016/R/IDR).

Estimated consumption

This is the water consumption in cubic metres that is attributed in the absence of detected readings or self-reportings and it is calculated by applying the average daily consumption to the number of days of the estimated period.

Consumption billed in the period

This is the water consumption in cubic metres that you are paying in the bill. It is determined by the actual consumption of the period, to which the estimated consumption of the current bill is added, and the estimated consumption already billed in the previous bills is subtracted.


Il conguaglio è la differenza tra i consumi stimati e quelli effettivi. Nella bolletta di conguaglio, i corrispettivi per il servizio sono calcolati su consumi determinati tra due letture effettive del contatore (eseguite da Gruppo CAP oppure trasmesse dal cliente). Vengono detratti gli importi precedentemente pagati con le bollette di acconto e l’importo indicato in bolletta costituisce l’eventuale saldo da pagare. Nel caso in cui gli acconti versati fossero stati superiori a quanto dovuto, la bolletta risulterà di importo negativo (bolletta negativa) e l’importo sarà o accreditato sulla bolletta successiva oppure rimborsato tramite bonifico sul conto corrente che sarà indicato dal cliente.

Integrated water service charter

This is the document required by the regulations with which the manager (CAP Group) undertakes to comply with certain quality standards that concern the maximum execution times of the main services. In the event of non-compliance with one of the standards, as a customer you are entitled to compensation that will be credited to your bill. If you want to consult the Charter, you can find it at the bottom of the page, request it by sending an email to or by calling Customer Service at +39 800.428.428.


There is also a variable component of aqueduct services that is divided into levels, i.e., by consumption brackets: a preferential tariff bracket only for residential users for domestic use and condominium use, which is 33 cubic metres per year per capita; a low-tariff bracket and three surplus brackets at increasing tariffs.

For household and condominium users, the maximum limits of the levels are equal to twice the previous level. The limit of the low-tariff level is twice the preferential limit, the first surplus limit is twice the low-tariff level, and so on. For non-domestic users, the first low-tariff level is valid up to 200 m3/year and the maximum limits of the subsequent levels are equal to three times the previous level.


È la situazione in cui il cliente si trova se non è in regola con il pagamento delle bollette. Il ritardo nel pagamento della bolletta comporta l’addebito di interessi di mora. Il mancato pagamento può portare in alcuni casi alla sospensione della fornitura.

Metro cubo (mc)

Il metro cubo (mc) è l'unità di misura generalmente utilizzata per indicare i consumi di acqua. Un metro cubo equivale a 1.000 litri.

Miscellaneous charges and credits

These include charges or credits other than those for the provision of aqueduct, sewage, treatment and fixed component services. They are instead linked, for example, to default interest or compensation provided for in the Integrated Water Service Charter. The bill must always highlight what they refer to and depending on their type they may or may not be subject to VAT.

Oneri di perequazione

Si tratta di addebiti a carico dei clienti del servizio idrico determinati dall’Autorità di Regolazione (ARERA) e volti a compensare costi sostenuti nell'interesse generale del sistema, quali ad esempio quelli riferiti ad agevolazioni tariffarie previste a favore delle utenze situate nei comuni danneggiati da eventi sismici (UI1), alla promozione della qualità del servizio (UI2), alla perequazione dei costi relativi all’erogazione del bonus sociale idrico (UI3) e alla copertura dei costi di gestione del Fondo di Garanzia delle opere idriche (UI4).

Quota fissa

È un importo addebitato in bolletta che si paga indipendentemente dal consumo e quantificata per singolo servizio erogato (acquedotto, fognatura e depurazione). Copre una parte dei costi fissi che il gestore sostiene per erogare i servizi. Per le utenze ad uso domestico residente è addebitata una quota fissa giornaliera pro capite in base al numero dei residenti fino a un massimo di tre persone per unità abitativa. Per le utenze domestiche non residenti e per le utenze condominiali è applicata in base al numero e alla destinazione d’uso delle unità immobiliari e per le utenze non domestiche in base al diametro del contatore.


È la suddivisione in rate dell'importo dovuto. La richiesta di rateizzazione del pagamento deve essere fatta entro 10 giorni dalla scadenza della bolletta, inviando una mail a oppure telefonando al servizio clienti 800.428.428.

Reading detected

Reading carried out by personnel appointed by the CAP Group, who detects the number shown on the meter on a certain date.

Integrated water service

These are together the aqueduct, sewer and treatment services. The bill includes charges for the costs of the three services, if due.


In order to be able to bill you for more realistic consumption, we ask for your cooperation, inviting you to periodically inform us of the reading of your meter. Each bill shows the period within which you can carry out the self-reporting.


Through the sewer service, sewage is collected and conveyed through the sewer network to the treatment plant. The fee for the sewer service consists of a fixed component, independent of consumption, and a variable component (€/m3) applied to the cubic metres of water consumed.

Security deposit paid

This is the amount paid as a security deposit as a guarantee of the payment of bills. The initial security deposit and any annual adjustments shall be paid in instalments in two bills starting from the first bill following the activation of the service, i.e., the annual recalculation. The deposit is determined as equal to the value of the amounts due for a maximum of three months of historical consumption and adjusted annually, in relation to the previous calendar year.


Through the treatment service, the water collected from the sewer is treated in special plants and made compatible with the environment so that it can be returned to the waterways. The fee for the sewer service consists of a fixed component, independent of consumption, and a variable component (€/m3) applied to the cubic metres of water consumed.

Water bonus

This corresponds to the amount relating to the social water bonus component credited in the bill and calculated based on the number of beneficiaries and days of consumption billed.