The standard rate of interest on ­general damages for pain and suffering and loss of amenities in personal injury cases was fixed at 2% a year by the House of Lords in Birkett v Hayes [1982] 1 WLR 816; [1982] 2 All ER 70. This was confirmed as appropriate by the Court of Appeal in Lawrence v Chief Constable of Staffordshire [2000], The Times, 25 July.

The appropriate rate of interest for special damages is the rate, over the period for which the interest is awarded, which is payable on the court special account. After seven years at 6%, this rate was reduced to 3% a year on 1 February 2009, to 1.5% on 1 June 2009, and to 0.5% on 1 July 2009. Interest since June 1987 has been paid daily on a 1/365th basis, even in a leap year such as 1992.

In cases of continuing special damages, half the appropriate rate from the date of injury to the date of trial is awarded. In cases where the special damages have ceased and are thus limited to a finite period, there are conflicting Court of Appeal decisions as to whether the award should be half the appropriate rate from injury to trial (Dexter v Courtaulds [1984] 1 All ER 70) or the full special account rate from a date within the period to which the special damages are limited (Prokop v DHSS [1985] CLY 1037). The House of Lords has confirmed that Department for Work and Pensions benefit should be disregarded when calculating interest on special damages (Wadey v Surrey County Council [2000] 1 WLR 820 (HL)).

The relevant rates since 1965, which are conveniently set out in the White Book at note 7.0.9, are reproduced in table three. Table 1 records the ­percentage total of these rates from January 1991. In the left-hand column is shown the month from the first day of which interest is assumed to run. The right-hand column shows the ­percentage interest accumulated from the first day of each month to 1 December 2011.

Continued use can be made of this table by adding to the figures therein 1/365th of the special account rate from 1 December 2011 onwards. Precision may easily be attained through table 2, which records the accumulated total of days at the end of each of the next six months.

Suppose that interest runs from 1 June 2003 to 13 February 2012. The total to the end of November 2011 is 36.38%. If the rate remains at 0.5% a year, the addition from 1 December 2011 to 13 February 2012 will be 0.5% x 75/365 = 0.10%. Thus the grand total from 1 June 2003 to 13 February 2012 will be 36.38 + 0.10 = 36.48%. These tables should assist all those concerned with interest since 1991 to make calculations fluently. The ­listed rates provide the base for a ­calculation from 1965. Although the tables’ ­primary application is to ­interest on special damages in ­personal injury cases, they are equally applicable to any other case in which the special account is used in calculating interest.

Andrew Morgan is a partner at Field Fisher Waterhouse

Table 1 - rates of interest on ­special account since 1991 (%) clear="all">

1991 1992 1993 1994 1995 1996 1997
January 137.15 125.04 114.76 106.57 98.57 90.57 82.55
February 135.94 124.17 113.89 105.89 97.89 89.89 81.87
March 134.85 123.35 113.28 105.28 97.28 89.25 81.25
April 133.64 122.48 112.6 104.6 96.6 88.57 80.57
May 132.65 121.64 111.94 103.94 95.94 87.92 79.92
June 131.63 120.77 111.26 103.26 95.26 87.24 79.24
July 130.65 119.93 110.6 102.6 94.6 86.58 78.58
August 129.63 119.06 109.92 101.92 93.92 85.9 77.9
September 128.61 118.19 109.24 101.24 93.24 85.22 77.22
October 127.62 117.34 108.58 100.58 92.58 84.56 76.56
November 126.75 116.47 107.91 99.91 91.91 83.88 75.88
December 125.91 115.63 107.25 99.25 91.25 83.23 75.23

1998 1999 2000 2001 2002 2003 2004
January 74.55 66.55 58.97 51.95 44.95 38.86 32.86
February 73.87 65.87 58.37 51.35 44.35 38.35 32.35
March 73.25 65.25 57.82 50.82 43.89 37.89 31.88
April 72.57 64.57 57.22 50.22 43.38 37.38 31.37
May 71.92 63.92 56.65 49.65 42.89 36.89 30.87
June 71.24 63.24 56.05 49.05 42.38 36.38 30.36
July 70.58 62.58 55.48 48.48 41.89 35.89 29.87
August 69.9 61.9 54.88 47.88 41.38 35.38 29.36
September 69.22 61.31 54.29 47.29 40.87 34.87 28.85
October 68.56 60.73 53.71 46.71 40.37 34.37 28.36
November 67.88 60.14 53.12 46.12 39.86 33.86 27.85
December 67.23 59.56 52.54 45.54 39.37 33.37 27.35

2005 2006 2007 2008 2009 2010 2011
January 26.85 20.85 14.85 8.85 2.83 0.96 0.46
February 26.34 20.34 14.34 8.34 2.32 0.92 0.42

March 25.88 19.88 13.88 7.86 2.09 0.88 0.38 April 25.37 19.37 13.37 7.35 1.83 0.83 0.33 May 24.87 18.87 12.87 6.86 1.59 0.79 0.29 June 24.36 18.36 12.36 6.35 1.33 0.75 0.25 July 23.87 17.87 11.87 5.85 1.21 0.71 0.21 August 23.36 17.36 11.36 5.34 1.17 0.67 0.17 September 22.85 16.85 10.85 4.83 1.12 0.62 0.12 October 22.36 16.36 10.36 4.34 1.08 0.58 0.08 November 21.85 15.85 9.85 3.83 1.04 0.54 0.04 December 21.35 15.35 9.35 3.34 1 0.5

Table two - accumulated total of days

Table three - rates of interest on special account since 1965

31 December 2011 31
31 January 2012 62
29 February 2012 91
31 March 2012 122
30 April 2012 152
31 May 2012 183
30 June 2012 213
From
1 October 1965 5%
1 September 1966 5.5%
1 March 1968 6%
1 March 1969 6.5%
1 March 1970 7%
1 April 1971 7.5%
1 March 1973 8%
1 March 1974 9%
1 February 1977 10%
1 March 1979 12.5%
1 January 1980 15%
1 January 1981 12.5%
1 December 1981 15%
1 March 1982 14%
1 July 1982 13%
1 April 1983 12.5%
1 April 1984 12%
1 August 1986 11.5%
1 January 1987 12.25%
1 April 1987 11.75%
1 November 1987 11.25%
1 December 1987 11%
1 May 1988 9.5%
1 August 1988 11%
1 November 1988 12.25%
1 January 1989 13%
1 November 1989 14.25%
1 April 1991 12%
1 October 1991 10.25%
1 February 1993 8%
1 August 1999 7%
1 February 2002 6%
1 February 2009 3%
1 June 2009 1.5%
1 July 2009 0.5%