Ulster Bank customers hit by the month-long IT meltdown which crippled the bank are to be offered a one-off 25 euro (£19) payment and free banking for three months.

Under a compensation package worth at least 35 million euro (£27 million), the bank will give the small payout to personal current account holders forced to use branch banking more often than normal.

Ulster Bank also vowed to waive certain fees, charges and surcharge interest for three months as it bids to rebuild its reputation among its 600,000 customers.

Jim Brown, Ulster Bank chief executive, said: "We recognise that we have work to do to restore our customers' trust in us and we believe that this is the first step in that direction. We have worked with our key stakeholders to ensure the additional measures which we are taking provide a comprehensive response to customer concerns and demonstrate our commitment to making amends."

Ulster Bank said it was offering the 25 euro to cover inconvenience caused by forcing customers to use branch services during the IT crisis between June 19 and July 18.

Customers are also told to claim from the bank for reasonable out-of-pocket expenses incurred during the technical chaos. The bank said it will start processing claims from Monday and has offered to top up personal and small business customers' losses by 20% up to a maximum payout of 120 euro (£95). It has urged customers to back up claims with paperwork such as phone bills, bus tickets, travel receipts, bills or invoices.

For customers with savings on deposit the bank has also offered a one-off payment. It will be the equivalent of an additional rate for three months of 0.06% gross, 0.25% on the average daily balance, between September 1 and November 30 this year. It will be automatic and applies to personal banking and small business customers with a savings account. Ulster Bank said any errors made on fees, charges and debit interest will be corrected by the end of October 2012.

The bank has also said that customers' credit rating will not be permanently affected by the banking breakdown. Free reports from the Irish Credit Bureau will be available within five days for customers who have any concerns.

The meltdown was caused when Ulster Bank's parent company, Royal Bank of Scotland (RBS), which has been bailed out by the UK Government, moved to upgrade its IT systems. Customers in Britain with RBS and another subsidiary, NatWest, had their ordinary banking services back up and running within days while the chaos lasted for a month in the Republic and Northern Ireland.

Elsewhere, Ulster Bank has given a commitment to delay the introduction of maintenance fees for all personal current account holders until July 2013.