Many companies are realising that they can save both money and time by only having to process pays every fortnight rather than every week.
If you are on a weekly pay frequency and you want to change it then you must negotiate the change with your staff prior to making the change. You are effectively changing the terms of your contract (be it written or implied) so you cannot just roll up one morning and announce that from next week staff will be paid fortnightly.
If you need help with this process then we sugguest you contact the guys at In Sync Business Consulting. Their details are under Companies we Like.