Securing a specific seat before travelling can make for a more comfortable flight if you are willing to pay the fee. However, according to one expert, there is one common mistake many people make when selecting.

Brenna Ryan from Victorian Plumbing explained that passengers should always consider their bathroom habits when booking a flight. She named the best and worst plane seats based on toilet access and revealed the seat travellers should avoid at all costs: “When choosing where to sit on a flight, there are a few important factors to note. Think about how often you visit the toilet. If the answer is pretty frequently, take that into account when deciding which seat to book."

The Victorian Plumbing expert recommended dodging the middle seats of the plane, saying, "The first thing to consider is which part of the plane to sit on. Planes usually have toilets both at the front and back, so look to sit there when possible and avoid the middle of the plane furthest from the toilets."

However, she warned against sitting too close to the conveniences due to likely queues.

"One thing to note when choosing a seat with good access to the toilet is that you don't want to be too close to the front or back of the plane”, said Brenna.

Sitting too close to the toilet can mean your seat is constantly blocked by people queuing to use the loo, which can be frustrating if you’re trying to sleep or want to get up.

The plumbing expert highlighted another grim reason to avoid toilets, suggesting that “there may even be a smell coming from them.”

Avoiding the very front and back rows, plus the middle section of the plane, aren’t the only places to avoid. Travellers should also take the position on each row into account.

Don’t book a window or middle seat if you anticipate frequent trips to the toilet or if you like to stretch your legs during a flight.

Brenna says the “very best seat option on a plane” is 4C. She suggests it offers a “comfortable and odourless trip with great toilet access”.

Meanwhile, 11A should be avoided. Brenna said this is “the worst seat on the plane” because it is far from the bathroom.

It is also a window seat, which makes it more difficult to manoeuvre out of for frequent bathroom breaks.

“Not only do these issues cause inconvenience, but the seat also boasts no windows, despite being a so-called window seat."