Welfare Reform Bill

My Lords, will my noble friend reflect, in conjunction with our noble friend his colleague, that in a sense—I have enjoyed watching the passing scene on this matter—he has been rescued by the fact that the concept of income tax is a tax from year to year and has a defined period in which adjustments can be made? But I understand that under the universal credit, the payment period will be somewhat different and the ability to use that kind of argument, if there were a miscalculation of the taper rate in the future, would not be available? That is perhaps the moral that Ministers and officials will need to take into account in avoiding any slip-ups in the future.