The five scams you meet on Black Friday revealed by National Police

They focus on five 'standard' types of fraud which come under the headings of 'carding', 'phishing', 'pharming', 'spamming' and 'vishing'.

'Carding', explains the police, is a fraudulent attempt to get a credit or debit card holder to provide his or her PIN number and may take many forms, but differs from 'phishing', which is where emails or adverts purport to be from genuine companies – the traditional form being an email from a bank which asks the account-holder to click on a link to re-set his or her password.

Companies do not normally do this unless a customer has already gone onto the genuine website and clicked the 'forgotten password' link, and banks never do so.

A genuine email of this type would have a padlock symbol in the address bar, although the safest option altogether is to enter the website in question separately by typing in the address in full.

'Pharming' involves a fraudulent racket supplanting a legal web domain which, when the user clicks on it, transfers them automatically to a fake site which in some way requests details of PINs or passwords.

'Spamming' is the most well-known of all likely scams, but can still be difficult to detect – taking the form of junk mail, messages claim to offer attractive discounts and free gifts which appear to be genuine marketing attempts.

'Vishing' is where users are encouraged to ring a given telephone number to obtain a special offer – sometimes these scams are transmitted by text message or request an SMS to be sent to get the discount in question, in which case they are known as 'SMishing'.

National Police warn 'Black Friday' bargain-hunters never to introduce their credit or debit card details onto websites they do not already know well and trust, and never to insert a PIN number on any site at all.

Even if the website seems genuine, they should check for the padlock icon in the address bar.

'Middleman' payment methods, such as via pre-paid cards, those with a low credit limit, or through PayPal are best, and anyone who shops online should check their bank and credit card statements regularly to keep an eye out for strange amounts or transactions recorded.

Many secure sites set up multiple protection barriers which are put in place by banks or card issuers – such as prompting a bank to send the account-holder a text message with coordinates for his or her security card, which features a list of numbers with a different one for each coordinate and with no two cards ever showing the same number combinations.

Double-safety methods are often employed with online banking – the account-holder needs a PIN to enter the account, then has to type in coordinates from his or her security card when making a transfer and, next, type in a code number sent via SMS.

National Police urge 'Black Friday' buyers to keep receipts in case goods are defective or they are overcharged.

The force's Technology Investigation Unit (UIT) warns that with online purchases and transactions becoming more and more commonplace, hackers and fraudsters are coming up with ever-more creative methods of seizing personal data to be able to access bank account contents.

“Loooots of common sense and prudence when buying this #BlackFriday. Follow our five recommendations and avoid being a victim of carding, phishing, pharming...” the National Police has warned on its Twitter site, @policia.

The photograph shows an example of the type of scam users may encounter, with 'Don't fall for it' in red block capitals.