With Greece's exit from the eurozone looking increasingly likely, financial experts around the world are speculating about the effect this will have on the global economy. Some say that the contagion could spread to Spain and Italy, banks that have lent money to Greece could suffer catastrophic losses, and the entire European monetary project could crumble.

Such an outcome would undoubtedly have massive technological implications for banks, as well as any companies that carry out payment transactions. The Financial Services Authority (FSA) has requested that banks make contingency plans towards the dismantling of the euro, and many financial institutions have already put operational strategies in place for dealing with any changes.

So what impact would Greece's departure from the euro have on the technological infrastructure that runs our payment systems, and what can banks do to avoid a financial meltdown?

Single Euro Payments Area

One key issue is that payments between European Union member states are currently treated as domestic, thanks to the Single Euro Payments Area (SEPA) – an initiative that allows cashless euro payments to be made to anyone located anywhere in the EU using a single bank account and a single set of payment instruments.

The aim of the initiative is to bolster the common currency by improving the efficiency of cross-border payments, and the industry has invested a great deal of money in developing a set of harmonised payment schemes and frameworks for electronic euro payments.

If one or more countries pulls out of the eurozone, banks will have to reprogram their systems to treat those countries' payments as non-domestic, and hence reapply fees and business rules for international payments, according to Rachel Hunt, head of IDC Financial Insights for EMEA.

However, some countries have already removed their legacy domestic payment systems, while others have yet to fully migrate domestic payment legacy infrastructures to SEPA platforms, making the situation extremely complex.

“The risk is confusion, outages and lack of transparency as all this recoding takes place,” said Hunt. “Obviously the gains from payments system consolidation will be removed, creating more fragmentation.”

Although Greece's exit from the euro would be disruptive, it would not be disastrous. Most banks also already operate multi-currency systems, so Greece could revert to the drachma and the rest of the eurozone would continue to use the SEPA payments infrastructure.

If Spain and Italy were also forced out, however, the euro itself could start to fissure, and countries might start turning away from SEPA altogether. The banks would then be faced with the prospect of millions of euros worth of investment going down the drain.

Chris Skinner, chief executive of The Financial Services Club, said that organisations could end up adapting their pan-European payment infrastructures to handle multiple currencies, rather than going back to the fragmented system they had before.

He said that many companies have now moved to cloud services and reinvigorated their payment systems to make them fit-for-purpose, regardless of gearing up for the introduction of SEPA and the euro, so even if the euro disappears they will still be fit-for-purpose.

“The bankers say that, even if the eurozone falls apart, SEPA is still going to be used because it is just going to be an efficient infrastructure that can be used within the EU, whether the euro exists or not. It's created a regional capability,” said Skinner.

However, he admitted that this was a philosophical way of viewing the situation, and that in reality “we'd all be really pissed off because we wasted so much in creating it”.