British regulators have fined Royal Bank of Scotland (RBS) and NatWest £14.5 million ($26.3 million) for suitability failings in their mortgage business.

The UK’s Financial Conduct Authority (FCA) levied the fines Wednesday, saying that the firms failed to ensure that advice given to customers was suitable. The regulator says that its reviews of the firms’ sales in 2012 found that in over half the cases the suitability of the advice was not clear. The suitability failures included failing to consider the full extent of a customer’s budget when making a recommendation, failing to properly advise customers who were looking to consolidate debt, and not advising customers about the appropriate term for their mortgage.

The FCA reports that the firms’ own mystery shopping efforts found advisors giving personal views on the future movement of interest rates. “This was highly inappropriate and may have resulted in the borrower being sold the wrong type of mortgage for them,” it says.

And, the regulator says that the firms did not adequately address these failings when it raised concerns about the quality of their advice processes, which resulted in customers being at risk for an even longer period. FCA predecessor, the Financial Services Authority (FSA) first flagged these issues in November 2011, but the FCA says that the firms did not begin to address them until the end of September 2012.

The FCA notes there’s no evidence that these suitability failings have caused widespread detriment so far. However, the firms have agreed to contact around 30,000 consumers to allow them to raise any concerns they have about the advice they received.

The firms agreed to settle the case at an early stage and qualified for a 30% discount on their fine. Otherwise, the fine would have been £20.7 million.

“Taking out a mortgage is one of the most important financial decisions we can make. Poor advice could cost someone their home so it’s vital that the advice process is fit for purpose. Both firms failed to ensure that their customers were getting the best advice for them,” said Tracey McDermott, director of enforcement and financial crime at the FCA.

“We made our concerns clear to the firms in November 2011 but it was almost a year later before the firms started to take proper steps to put things right. Where we raise concerns with firms we expect them to take effective action to resolve them without delay. This simply failed to happen in this case,” she added.

RBS and NatWest report that at the end of November 2012 they completely overhauled their mortgage sales process, re-trained all of their advisors, and accredited them on a new sales process.

“Taking out a mortgage is one of the biggest moments in our lives, and our customers have every right to expect the very best service when making this decision. It is clear that in the past the bank just didn’t get this right, this was unacceptable and should never have happened,” said Ross McEwan, CEO of RBS and NatWest. “We have worked hard to put things right. When I joined the bank we completely overhauled our processes, and took all our mortgage advisers off the front line for an extensive period of time to get the training required.”

“Today’s notice shows that we still have challenges to face, but we are determined to take the steps needed to earn back our customers’ trust,” he added.