You should read the notes here
as part of this answer.
Normally, the pension contribution is deducted from your gross pay and the tax is then calculated on your net of pension deduction pay
(the net pay route). That way, you get tax relief at whatever tax rate you would have paid tax at had the contribution not been deducted first. The problem with this is that as you had three jobs with possibly more than running at the same time, you may not have got the correct amount of tax relief on some of your pension contributions as both sets of earnings may have been taxed at 20% instead of some at 20% and some at 40% if the combined total was high enough. Whether you were liable to tax at 40% would depend on the sum total of your income from all sources.
The other way of employers dealing with pension contributions is the relief at source method. You pay a net of 20% tax relief contribution from your after tax pay
and the pension provider claims the 20% tax relief from the tax office and adds it to your pension plan. If you are a higher rate taxpayer, you need to claim the additional tax relief that you are entitled to. See below.
You need to find out from the NHS how your pension contributions are accounted for, ie vis the net pay scheme or the relief at source scheme.
The figures that you should have entered in your tax return for each period of employment with the NHS are the gross pay and tax figures from your P60s and your P45s and you appear to have done this correctly. What you need to work out is whether your gross income for 2012/13 (the three gross pay figures added together exceeded £42,375, above which you pay tax at 40%.
You should get a statement from the NHS showing your pension contributions and send it to the tax office for them to assess whether you are due any extra tax relief. If some of your pension contributions were not deducted from your pay before tax was worked out, you would put the contribution figure in box 3 of the pension section at the top of page TR4 of the SA100
tax return. See the notes on page TR18 here
. You can amend the return online if you need to.
I hope this helps but let me know if you have any further questions.