Taxi drivers in Liverpool are warning passengers to look out for a specific sign to avoid getting ripped off if they are out and about in the city this weekend.
Several people have reported attempts by some black cab drivers to charge customers more than they should - while still technically being on the meter.
While the majority of cabbies working in the city are reliable and honest - there are some who are relying on people's lack of knowledge of the trade to make some extra cash.
And now the city's good cabbies are warning about one particular scam that could see passengers forking out more than they should be.
People have reported getting into a cab in recent weeks and noticing that the taxi meter is displaying an X as they set off.
Now this might not mean a lot to some people - particularly those without a working knowledge of taxi pricing structures, but it is something to watch out for.
The X is also known as Extra Rate or Tariff 3 and should should only be in operation for journeys between 6pm on December 24 and 6am on December 27 and between 6pm on December 27 and 6am on January 2, when higher charges will come in.
The only other time that you should see the X rate in use is when a journey takes you four miles beyond the city boundary of Liverpool.
But this clearly isn't always how it is being used.
One Twitter user detailed their experience last week, tweeting: "Got in the taxi with three friends on Bold street heading out of town.
"I saw it was on X rate and asked him why that was. He told us to get out an refused to answer and take us any further."
And according to city cabbies, it is a fairly common practice, which is particularly used to target people from outside of the city.
One driver, who didn't want to be named, but has helped the ECHO to expose some dodgy cabbie actions in the past said: "We have all heard of drivers trying this. I have seen it happening at Lime Street Station on people who clearly haven't got a Scouse accent and don't know - it is scandalous.
"It is things like this that mean people aren't getting black cabs, we have to stop people from killing our trade."
So for those that don't know, we have made this handy guide for what rate should apply at what time - and how you can identify if you are being ripped off.
The day rate for hackney carriages in Liverpool should be operated for any journeys starting after 6am and ending before 11pm.
Under this day rate, the first 330 yards of a fare is charged at £2.60.
Following this, a charge of 20 pence is added for every 232 to 19360 yards with a further 20 pence added for every 300 yards after that.
There is also a 20 pence charge added for every 60 seconds that a cab is waiting.
The night rate for hackney cabs in Liverpool is indicated by the letter n appearing on the left hand side of the meter.
The standard night rate should be in operation for any journeys starting after 11pm and ending before 6am.
For this rate, a fee of £3.25 should be charged for the first 330 yards of a journey.
Following this, 25 pence should be added for every subsequent 232 to 19360 yards.
Then 25 pence is added for each succeeding 300 yards.
Thirty pence is added on for every 60 seconds that the cab is waiting.
Tariff three - which is indicated by an X on the left hand side of the taxi meter - should be in operation for journeys between 6pm on December 24 and 6am on December 27.
The tariff is then in use again between 6pm on December 27 and 6am on January 2.
When this rate is in operation, a £3.90 charge is given for the first 330 yards of a journey.
This is added to by 30 pence for each subsequent 232 to 19360 yards.
Another 30 pence is added for each of the next 300 yards - with a 30 pence charge for every 60 seconds of waiting.
Now this bit is important - and is something many people may not be aware of.
The above pricing structure applies for journeys to destinations wholly within the City of Liverpool and ending at any point LESS than four miles beyond the nearest boundary of Liverpool.
According to the city council fare structure, when journeys are ending four or more miles beyond the nearest boundary of the city of Liverpool, the driver is not obliged to accept the fare.
But if they do, they can either agree the rate of fare (such as X) before the journey - or they must engage the relevant rate - and must not demand a fare greater than what the meter shows.