Changing Sterling to Euro

What is the cheapest way of changing a large sum of Sterling to Euro and the best way of transferring it to Ireland? It's for the purchase of a holiday home by a UK resident.

Check out Currencyfair.com - excellent service and rates in my view. I'v used them several times.

No affiliation other than as customer.

Currencyfair.com - very easy to use, excellent rates & they only charge €3 per transfer.

My husband & I use it a few times each month to transfer his sterling wages into our joint Euro account and it is hassle free.