The Costs Practice Direction (Parts 43 to 48) Section 6 is still out there.
With the advent of the Jackson reforms proportionality and unreasonably incurred costs remain very much in the spotlight.
The preparation of inaccurate costs estimates, particularly , late on in the proceedings, gives the paying party a very effective stick with which to beat the receiving party.
Paragraph 6.5 provides that where there is a difference of 20% or more between the base costs claimed by the receiving party and the costs estimate served on the paying party then the receiving party must serve a statement of reasons accounting for the difference.
If the costs estimate is simply inaccurate then there is not much hope of justifying the difference. This leaves the door open for the Court to regard the difference between the estimate and the costs claimed as being disproportionate and/or unreasonable.
This, of course, serves to emphasise the fact that the preparation of the costs estimate should not be left in the hands of those inexperienced in the task.
It must also be remembered that to prepare an accurate costs estimate can take time. Do allow enough time for the task.