Permanent TSB has admitted it is having to deal with a high volume of customer complaints.

The bank is trying to integrate large chunks of Ulster Bank’s business that it bought into its operations.

The admission comes days after Bank of Ireland owned up to a blunder in the administration of 35,000 of the 70,000 mortgages it took over from KBC Bank.

Permanent TSB has said it has taken on extra staff to deal with the increasing number of complaints.

In a letter to a customer, a senior executive of the bank said: “We are currently experiencing an unprecedented high volume of complaints, and while we are doing out utmost to ensure all our customers receive a timely resolution to the issues they have raised, in some instances it is taking longer than anticipated to investigate these complaints.

“We have taken on extra staff to tackle the high volume of complaints, and I hope that my response clarifies your complaint.”

Asked about the letter, the bank said its customer resolution centre has to deal with higher numbers of complaints “from time to time”.

When this happens, it increases staffing in the complaints department.

“The bank has now significantly increased the size of the team managing complaints to improve the customer experience,” a spokesperson said.

“In all instances, customers’ regulatory protections remain in place and the bank will regularly correspond with customers over the course of an active complaint investigation to keep them updated on the progress of same.”

Last month, the Financial Services and Pensions Ombudsman said Permanent TSB had the second-greatest number of complaints against it upheld, substantially upheld or partially upheld, after Bank of Ireland. 

Permanent TSB was at the centre of nine cases.

The bank has opened thousands of new accounts as consumers seek alternatives to the departing Ulster and KBC.

Permanent TSB has taken over loans, branches and staff from Ulster Bank.

It recently completed the acquisition of Ulster Bank’s €165m performing micro-SME loan book following the successful transfer of around 3,200 loan accounts.

It also bought €5.2bn of performing non-tracker residential mortgages in November from Ulster Bank and took control of 25 former Ulster Bank branches in January.

It is also taking on €900m of non-tracker residential mortgages, along with the entire Lombard asset finance business, from Ulster Bank.

To date, more than 250 Ulster Bank employees have transferred to Permanent TSB as part of the transaction.

In the past few days, Bank of Ireland admitted it made a blunder on thousands of mortgage accounts it took over from KBC Bank.

The error is likely to mean some former KBC customers will be turned down for loans while the issue is being resolved.

Around 35,000 mortgage holders are affected, which is around half of the number bought from KBC.

Bank of Ireland has written to mortgage holders who transferred to it from KBC, telling them the error it made was “at the point your mortgage loan transferred from KBC to BoI, which resulted in your mortgage ‘start date’ being incorrectly input”.