Bailiff charged interest not awarded on the judgment.
Statutory interest is not automatic. The law only gives a "power to award" interest. Therefore, it must be claimed, hence a judgment "claimant"
You can download a copy of the judgment by searching yourself on Registry Trust Online and looking at the judgment to see whether interest had been awarded on the original judgment
If the interest award is absent on the judgment and you were charged interest by the bailiff, you can do a reclaim against the original creditor in the small claims court.
If the bailiff charged you fees according to the sum recovered that included interest, you can apply to the court to assess those fees in a detailed assessment hearing.
Here is a simple interest calculator.
The Law:
Section 69 of the County Courts Act 1984 states:
(1)Subject to rules of court, in proceedings (whenever instituted) before the county court for the recovery of a debt or damages there may be included in any sum for which judgment is given simple interest, at such rate as the court thinks fit or as may be prescribed, on all or any part of the debt or damages in respect of which judgment is given, or payment is made before judgment, for all or any part of the period between the date when the cause of action arose and—
(4)Interest in respect of a debt shall not be awarded under this section for a period during which, for whatever reason, interest on the debt already runs.
(5)Interest under this section may be calculated at different rates in respect of different periods.
(6)In this section "plaintiff" means the person seeking the debt or damages and "defendant" means the person from whom the plaintiff seeks the debt or damages and "personal injuries" includes any disease and any impairment of a person’s physical or mental condition.
(7)Nothing in this section affects the damages recoverable for the dishonour of a bill of exchange.
(8)In determining whether the amount of any debt or damages exceeds that prescribed by or under any enactment, no account shall be taken of any interest payable by virtue of this section except where express provision to the contrary is made by or under that or any other enactment.