All passengers must have a valid ticket. Law no. 28/2006 of 4 July says the lack of a valid ticket, showing an invalid ticket or refusing to show a ticket when using the public passenger transport system is punishable by a fine. This follows from the terms of article 7 of Law no. 28/2006, of 4 July, as amended by Decree-Law no. 117/2017 of 12 September, and a notice is issued under the terms of Ordinance no. 37/2018 of 29 January.
Use begins when the passenger passes the train entrance gates or enters the train station access bay, in cases where access is limited, and continues as long as they do not leave via the exit channels. 
The access and exit channels are delimited by the line defined by the validators in the station concourse, fixed devices designed to control entry and exit, or any type of signage designed for this purpose.

Passengers must be in possession of a valid ticket for the route/class and train of the journey to use the transport services. See the conditions of use above. Do not travel without a valid ticket.
Tickets cannot be bought on board, except under the terms of the law, and the unavailability of means of payment. Insufficient change or limitations imposed by the sales equipment or the impossibility of paying by ATM cannot be invoked as a reason for not purchasing tickets, provided they are available at the boarding point around the station.
If there is no other means of sale available, passengers can buy a ticket on the train, if they speak to the ticket inspector immediately after boarding and before taking their seat.
When purchasing tickets, passengers must act in good faith and not present notes of disproportionately high value in relation to the value of the ticket to be purchased as a means of payment. 

Lisbon Urban Trains
Transport tickets can be purchased from ticket offices and vending machines at stations. The Navegante pass can also be topped up at ATMs.
Passengers must respect the queues when purchasing tickets and entering or exiting the access gates.

Porto Urban Trains
Transport tickets can be purchased from ticket offices, vending machines at stations or payshop agents.
The vending machines will only accept notes for the purchase of a ticket requiring change of less than €10 (ten euros). 
CP does not guarantee change in vending machines and passengers must make sure they have enough change to buy tickets from these machines. 
Passengers must press the button for a receipt during the payment process if they want proof of purchase. Receipts cannot be issued once the operation has been completed. 

Alfa Pendular and Intercidades
Tickets can be purchased at ticket offices, the online Ticket Office, CP App, the Customer Care Line, from Travel Agencies or on the OMIO platform. 

Regional and InterRegional
Tickets can be purchased at ticket offices, the online Ticket Office, CP App, the Customer Care Line and Travel Agencies. 

Celta International
Tickets can be purchased at ticket offices or on the RENFE website.

Coimbra Urban Trains
Tickets can be purchased at ticket offices, the online Ticket Office, CP App, the Customer Care Line and Travel Agencies.

Passengers must validate their tickets before the start of each journey on the Lisbon and Porto urban trains. Tickets are only valid after having been validated. 
All tickets, including passes, must be validated before the start of each journey, in accordance with Law no. 28/2006 of 4 July, as amended by Decree-Law no. 117/2017 of 12 September.

Lisbon urban trains 
If there are no access channels, go to the validators at the station to validate your ticket. Hold your ticket or pass over the validation point, without moving it, and wait for the green light to come on and the validation completed message to appear. 
In stations with access channels, validate at the entrance and exit of the stations, even if the access channels are open. Wait for the access channels to close after the passenger in front of you has passed through, then hold your card as shown for reading. Wait for the green light to appear on the display and for the doors to open.
Do not pass through the access channels leaning against another customer. If you do, you may be trapped and you will be guilty trespass.
The wider access channels in the stations, known as the ‘Special Channel’, are intended for passengers with reduced mobility, pushchairs, parents with young children, bicycles or large packages.
The Special Channel is used for entering and exiting the station, so be aware and only pass when the green arrow is lit.
If you need support, there is a help button in the station access channels and ticket vending machines that you can use whenever you need information.

Porto Urban Trains
Passengers must validate their tickets before each journey no more than 15 minutes before the train's scheduled departure time, except for transfers. 
If you want to travel beyond the origin or destination of your ticket, you must buy an extra ticket for the missing part of the journey before boarding.
If you haven’t done so, you can speak to the ticket inspector right after boarding — and always before reaching the last station covered by your original ticket — to request validation.
Contactless card must not be validated next to other contactless cards. Otherwise you run the risk of the validator triggering the validation (and consumption of the balance) of all the cards, of the card it recognises first (which may not be the one you wanted) or of none of them being validated, incurring all the risks inherent in this.

You must keep your card in good working order throughout your journey, particularly until you leave the station. You must present your ticket to the ticket inspectors whenever requested to do so.

Alfa Pendular, Intercidades, Regional, InterRegional, International and Coimbra Urban Trains
A lack of a ticket, namely due to loss, destruction or misplacement of the ticket, is considered a serious administrative offence under the terms of Law no. 28/2006 of 4 July, as amended by Decree-Law no. 117/2017 of 12 September.

Lisbon and Porto urban trains
Tickets and passes are loaded onto a rechargeable card. The receipt for your ticket or pass must always accompany your card, which is an integral part of the ticket and must be kept in good condition. 
Customers must keep the receipt until the ticket expires. 

The lack of a valid ticket or pass is an administrative offence. These can be simple or serious, as stipulated in Article 7 of Law no. 28/2006 of 4 July, as amended by Decree-Law no. 117/2017 of 12 September, and the corresponding fine is issued under the terms of Ordinance 355/2019 of 7 October. 
In the case of a serious administrative offence. Passengers without a valid ticket is subject to a fine of at least €120 and no more than €350 if the offence is committed on urban and regional routes of up to 50 km, or a fine of at least €250 and no more than €700 if it is committed on regional trains of more than 50 km, inter-regional trains and long-distance trains. 
Once the customer has been notified of the offence and the penalty and has received a notice to pay the fine, they can voluntarily pay the fine at any CP ticket office within 15 working days. This payment is made for the minimum amount of the corresponding fine, reduced by 50%, under the terms of article 9-A of Law no. 28/2006 of 4 July, as amended by Decree-Law no. 117/2017 of 12 September.

• Never cross the yellow platform line before the train stops;
• When travelling with small children, always hold their hand;
• Avoid crowding around the doors, making it easier for passengers to get on and off;
• Do not try to get on or off after the door closes;
• Mind the gap between the train and the platforms;
• Help others when using escalators. Keep to the right-hand side.