My wife is a Civil Servant and is due to retire at the end of this year. I am retired over a year and am in receipt of a Superannuation Pension from the HSE and a Social Welfare Invalidity pension. Neither my wife`s nor my income fluctuates. Yet we are on this Week 1/Month 1 assessment and we get amended tax Credit Certs approximately every 2 weeks, where my tax is different. I never know what I`m going to get any month as its my Superannuation that`s affected. Can anyone tell me how this can be and why cant they take the same amount every month so I know where I stand ? I have written to them for an explanation but got no reply. I would be most grateful if anyone could explain this to me. Thank you in advance.