Sky is offering subscribers to its discounted Unlimited Broadband package a £50 prepaid MasterCard.
People who sign up will receive broadband speeds of up to 17Mbps and unlimited downloads.
The 12-month contract costs £18 a month, plus a £9.95 set-up cost.
This means subscribers will get a broadband discount of £120 across the year, along with a line rental discount worth £11.88 and a broadband activation discount worth £10.
A £50 prepaid MasterCard is also being offered as a freebie with some of Sky's fibre broadband packages, including the Sky Fibre Max deal.
This option enables subscribers to receive broadband speeds of up to 76Mbps and unlimited downloads.
The 18-month contract costs £37 a month, along with a £59.95 set-up fee. Subscribers will therefore get a broadband discount worth £125.82 across the year.