Yes, 0800 numbers are free to call on Sky Talk. Like 0808 numbers, they are freephone numbers which since 1st June 2015 have been free to call from all UK landline and mobile phones.
Prior to June 2015 freephone numbers were free on landlines but not free on most mobiles – this is due to historic issues where mobile phones were rarely used so the term freephone only needed to apply to landline telephones. Since the boom of mobile phones though, Ofcom has received heavy criticism for the discrepancy and confusion surrounding the cost of calling different types of numbers from different types of devices. The new regulations which came into force on 1st June 2015 to reform UK call costs put this right, by ensuring that mobile phones follow suit with landline phones in honouring the freeness of freephone numbers. As a result, all UK freephone numbers, including 0800 and 0808 numbers, with the exception of the deprecated 0500 number range, are now completely free to call from all UK landlines and mobiles including those operating on the Sky Talk network.
Further info on Sky Talk call costs
To learn more about call costs on Sky Talk, call Sky on their freephone customer service number 0800 151 2747.