If you’re still using an 1850, 1890 or 076 number to ring any company that you deal with you’ll need to update your address book.
From December 31st 1850, 1890 and 076 numbers are being withdrawn. They’ll stop working entirely.
Businesses can still use the non-geographic 0818 numbers or freephone 1800 ones, though the free phone option obviously costs a business a lot more to maintain.
Most businesses and other organisations should have made the switch by now as the change was announced 3 years ago!
More information is available on the Comreg site.