Problem with landline number in contacts

To start with I'm in the UK.

If I try to enter a landline number into my contacts it ends up with spaces between numbers.

Lets say the number is, 01233 123654. When I enter it in to contacts it appears as 012 33 12 36 54. When I try to dial the number of cause it won't connect. Mobile numbers enter correct, no problem. If I dial number manually on the keys there's no problem.

Any idea what's happening?

Thanks