By Eran Kinsbruner, Technical Evangelist at Perfecto Mobile.

The tension between consumers and banks has been somewhat eased by mobile apps. Customers can now do a lot more through an app, in real time, when they need to – check a balance, pay a bill, make a transfer.

But these capabilities are to be expected. To stand out in a crowded field, banks must be delivering leading-edge features like fingerprint log-ins, facial recognition and pre-login access to account balances, to name a few.

However, given the ferocious competition and rapid migration to mobile in banking,it’s a challenge for digital teams to keep up with the pace of innovation and assure a flawless user experience on any device, OS version, screen size and network.

As with any industry, slow innovation and poorly tested apps will damage a brand and bottom line. But the consequences can be even worse in banking as it gets easier for fickle users to switch banks if an app performs poorly. More than a million people in the UK switched banks in the first quarter of 2015, up 7% over the previous year, according to data released by the Payments Council, a group that sets strategy for payment systems in the UK.

Mobile apps have infiltrated banking so significantly that banks are closing branches. UK banking upstarts like Atom and Starling — which have no branches and rely solely on a mobile app — are seizing the moment to gain market share, especially among the millennials demographic. With fewer operational costs, these companies have more room for innovation.

These days, if a bank is updating its app four times a year, it’s going slower than the market, and is less likely to attract and keep millennials: also known as “the future of your business.”

Here’s an example of the price of poor app performance in banking: Let’s say your “cheque capture” feature is not working – or God forbid you don’t have that feature. Your customers will either call customer service and complain, go to an ATM and deposit the cheque, or delete the app and switch banks. All of these alternatives cost the bank money. Now, a 55-year-old may not switch banks impulsively, but a 27-year-old probably will.

This puts pressure on UK’s established banks to take control of this wave of app innovation before branchless, mobile-only banks can poach customers.

Effective testing and monitoring is an important stage in the app development lifecycle for banking and other types of apps. We found in our own customer research that a whopping 44% of app defects are discovered by users (based on 900 survey respondents), with the top three reasons listed as “insufficient device coverage”, “lack of reliable automation” and the “need for more time for testing”.

There’s no excuse for making your users your testers. Perfecto Mobile has the advantage of having half of the leading UK banks as customers. We’ve seen how traditional banks initially tried to win the mobile rat race by just adding features to an app, but then came to realize that a transition to a continuous quality, cloud-based strategy that utilizes automated testing on a variety of real devices is the best way to deliver a flawless mobile user experience.

Take Lloyds Bank. It was one of the first banks to push the mobile envelope with app features like loan calculators, product comparison tools and tailored cash-back offers based on customers’ past transactions. Lloyds’ app was spotlighted recently by Forrester Research for having the most capable mobile services of any UK bank.

What is Lloyds doing right? Sure, they’re adding cutting-edge features, but the bank is also laser-focused on continuous app quality through rigorous testing. Lloyds knows that mobile excellence in banking is about much more than supporting the Apple Watch; it’s about your app working perfectly whenever a mobile user needs it. To that end, Lloyds uses a cloud-based lab that allows them to do performance testing on all their apps and websites under real world conditions on the right mix of devices before rolling services out to real users.

Another of our customers, also a top UK bank, is an active user of production monitoring to stay ahead of inevitable post-production glitches that, if neglected, set off a flurry of brand-damaging angry tweets and two-star app store ratings.

With monitoring, this bank’s dev/test teams are more proactive when there’s an outage or when key benchmarks – such as how long it takes to log in – that were set in pre-production are not quite playing out in real life. Glitches still happen despite thorough testing; monitoring lets you fix them before your customers know they happened.

To stave off the user frustration that leads to abandonment, banks need to put apps through their paces before and after production across a broad range of devices, operating systems and networks.

Your bank may have branch offices all over town. You may even be a household name. But that won’t be enough to save you if your mobile app keeps letting customers down.