Chippie you are incorrect
No, I'm not
http://www.hmrc.gov.uk/forms/p60.pdf
Shows a proforma p60 with the mandatory fields. The refund due is under the "pay and Income Tax Details", and the vast majority of employers will include this field. Its been several years since i have had to design a p60 for a company, but last time I check the Mark R for refund field was a mandatory field
That box entitled "if refund mark 'R'", not "you are due a refund".
The purpose of that box is to show if the total tax paid
in that employment was in fact a negative value, and therefore the individual received a net refund of tax in that employment.
This would happen in a number of situations. For instance, you worked from April to January in one job, and then changed jobs. Like a good employee you handed your P45 to your new employer. In the old job you earnt loads more than the new job, and were paying tax accordingly. When your new employer, who pays much much less, pays you, they use the total pay and tax to date figures from the last payroll, or from the p45 (whichever is latest) and look up on the tax tables how much tax you should have paid to on the total earnings to date. If the amount of tax you should have paid is less than what you have paid, they will pay you back the difference, so from that employer you will pay negative tax, and in that case they will put an R after that figure on the P60.
Plus you only need to complete a P50 if you are entirely sure you will not be working again in this tax year. If you are going to carry on working or intend to work again in this tax year then a P50 is unnecessary.
Again, not correct. That is one of the circumstances when you will use a P50. You can use a P50 if you know you will work again in that tax year. Fill it in appropriately, and send it back with your P45, and HMRC will issue you with an appropriate refund
up to the date you signed the p50 and reissue a new P45 with the updated amount of tax paid on it.