Typically, banks and money changers require a fee for their services.
It is also up to them to decide the rate the money is exchanged.
All this could now change with a new platform called Marco Polee.
Co-founder of the start-up, Mr Reuben So, 29, became frustrated with how money is exchanged and wanted to give others an alternative.
During a recent trip to Hungary, the Australian said he spent 30 per cent of what he had on money changers alone.
He told The New Paper: "The exchange rates (at the money changer for Hungary's forint) were absolutely ridiculous... But I had no choice, and it really hurt me."
This is not unusual for travellers: A simple act of changing currency can end up costing a lot.
Mr Ecko Tam, 28, a Hong Kong citizen who co-founded Marco Polee with Mr So in 2013, told TNP: "We currently don't make any money. We are focused on solving an unchallenged foreign exchange market and providing our users with a better option to save money."
Because the system, which was fully fleshed out and available for use in September last year, is a peer-to-peer exchange, the co-founders and their team are not taking any fees from the transactions.
This is unlike other peer-to-peer currency exchange platforms, such as TransferWise and CurrencyFair, that require fees or commissions for their services.
Marco Polee works much like typical online marketplace apps, such as Carousell and Trezo.
First, you put a listing on the website with the currency you are exchanging and the amount.
The live currency updating system taken from Open Exchange Rates, an external paid service, will convert the rates accordingly.
The rates are updated hourly with an option to lock the exchange rate to the time you keyed in your amount.
Once that is done, you wait for someone to accept your exchange. Amounts exchanged can be negotiated.
Once all is agreed, you will exchange the money face to face at a convenient time and place.
The average amount of money exchanged so far is $650, and there is an average of 50 listings created weekly. There is no cap on how much is exchanged.
So far, the most exchanged currencies on Marco Polee are the Singapore dollar, the Indonesian rupiah and the Thai baht.
Users must verify their social media or e-mail contacts before being able to list an exchange and those who are exchanging will also need to verify their mobile number. Mr So said this acts as their security check.
Lawyer Ravinderpal Singh, 46, told TNP that on the face of it, what the founders of Marco Polee are doing is legal.He said: "If they earn a commission from the exchange, they may have to apply for a registration. But it only brings people together and the founders are not making any money."
Another lawyer, Mr James Ow Yong, 29, said: "The site does not appear to engage in the buying or selling of foreign currency, nor does it charge a fee or commission from these transactions."
Because of this, he said that it does not fall under the definition of "money-changing business" for the purposes of the Money-changing and Remittance Businesses Act, which would require a licence.
When asked, Mr Tam told TNP: "We have actually checked this against the Singapore regulations and laws before we launched it into Singapore.
"As a platform, we never touch any form or cash or money and we don't profit from this platform, so it doesn't not fall under the standard foreign exchange currency regulations."
These men believe in the start-up so much that they have contributed about $30,000 of their own money towards it.
Mr So said that although the exchange service will always remain free, they plan on earning money from Marco Polee through means such as special listings. These include group exchanges where two or three people exchange cash among one another.
These plans are still in the pipeline, but Mr Yong said that if listing or transaction fees are charged, the site may then be required to be licensed.
For now, the service is only available on marcopolee.com, but its founders are working on an app for it this year.
They are also looking to expand into other countries soon.