Clerical Checking / Error Detection
What the section tests
Clerical checking asks you to compare data and spot the one detail that differs: names, reference numbers, dates, amounts, addresses or codes on a copy against a master list. Variants include alphabetical filing, sorting into sequence, checking totals, and applying simple coding rules to records.
How to compare reliably
Work in fixed chunks rather than reading whole strings. Check the length first - a missing or extra character is instantly wrong - then compare in blocks of three or four characters, left to right. When two strings look identical, scan them again from right to left; the eye tends to skip the middle of a familiar-looking string.
Recurring traps
- Transposed digits: 40218 versus 40281.
- Look-alike characters: O/0, I/1/l, S/5, B/8, G/6, rn/m.
- Doubled or dropped letters in surnames: Barret versus Barrett.
- Punctuation and spacing differences: hyphen, apostrophe, double space.
- Date format confusion: 03/04 could be 3 April or 4 March.
- Amounts: £1,240.00 versus £1,240.0, or a shifted decimal point.
- Stopping at the first familiar word and assuming the rest matches.
Worked example
Master: MR-40218-K. Copy: MR-40281-K.
The length matches and the prefix matches, so the difference lies in the number block: 40218 versus 40281. The 1 and 8 are transposed, so the copy is wrong.
Rule of thumb
Compare, do not read. Chunk it, check length first, and verify the middle as carefully as the ends.