Since Excel 2007 (Windows) and Excel 2008 (Mac), the number of rows in a .xlsx, .xlsm or .xlsb worksheet is fixed at 1,048,576. That is 2^20. Excel only stores the data and formatting actually used, so there is no penalty for having such a large number of rows in every worksheet. The file format isn't being changed for Excel 2016, so the same maximum number of rows still applies.
Using your money in Ireland: Northern Ireland and the Republic of Ireland have different currencies. In the Republic of Ireland the currency used is the Euro and in Northern Ireland the currency used is the Pound Sterling.
The Republic of Ireland uses the Euro, made up of 100 cents and Northern Ireland uses the Pound Sterling, made up of 100 pennies. The Republic of Ireland is part of the European Union and has adopted the Euro as its currency in common with many other members of the Union. In contrast Northern Ireland which is, for the time being, part of the United Kingdom continues to use the Pound Sterling as the UK has not adopted the Euro as its currency.