Sony has suspended the option to redeem voucher codes on PlayStation 4 as part of an ongoing attempt to stabilise PlayStation Network.

In an update on PlayStation Blog, Sony reiterated that it was "aware that users are experiencing some disruption to the PSN service. To minimise the inconvenience we have suspended the 'redeem voucher' functionality whilst we investigate further.

"Unfortunately this means that money cards, product vouchers, PlayStation Plus vouchers, PS3-PS4 upgrade vouchers and any other vouchers for digital content are not redeemable at this stage. Other PSN features such as log-in, online multi-player gaming, PlayStation Plus trial, PS Store (excluding voucher redemption), trophies, messages, friends etc. are all available.

"We apologise and will provide an update to this announcement soon."

Voucher redemption is the third feature to be suspended on PSN, joining the 'What's New' and 'Content Information Screen' functionality which had already been disabled to help alleviate server load.

Multiple users - included - have experienced trouble logging into PSN following the launch of PS4 earlier today.

Yesterday, Sony said that it expected to see a "record number" of players attempting to log in to the service as a result of PlayStation 4's European launch.