There are several reasons why this happens.

1.  Up until the 19th century there were no standardized spellings for surnames.  Also, many people rarely wrote their own name and many of the documents that we use in family history have been written by someone who has been given the name orally.  For example, when one of my Reid ancestors got married, he would give his name to the presiding vicar (or in this case, priest, as they were Catholics!), who would write it down as he heard it.  Therefore, this line of my family can be found under REID, REED or READ – and possibly even REDE.

2.  Foreign immigrants often anglicized their names because the local people found their name difficult to pronounce, or because they wanted to fit in with the local community, or because of discrimination.  The German name, ALBRECHT could therefore become ALLBRIGHT, and the Jewish name COHEN could become KAHN.

3.  Heavy accents could result in surnames being mis-heard when given to someone from a different area.  This could be the case if your ancestors have moved from place to place.

4.  Where surnames have been indexed in more recent times, the indexers have had to decipher some difficult handwriting, and very often names have therefore been mis-spelt.

This means that when you are researching your family, you will often need to check out various spellings before you find the right entry.

In some cases, this can be quite tedious, as I have found with my maternal grandfather, whose actual birth name (he was adopted) was MCEWEN.  I have found the following possibilies for this surname and there are many more: MCKOWAN, MCEWEN, MCEWAN, MAGOWEN, MCKEON, MCKEOWN, MCKEWEN, MCKEWAN, MCCUNE and so on.

This problem is solved to a large extent by the fact that most indexes search phonetically (though you can opt to search for an exact spelling if you wish).  However, these do not always cover every possibility, and it may sometimes be necessary to use your imagination and try a few different spellings in the search box.

For example, in parts of Northamptonshire, I once discoverd that the name PETTIFER had evolved from the 17th century name of PECKOVER.

Try saying the name out loud with the dialect of the region and seeing how the vowel sounds flatten or widen.  And what about if the person saying the name had a cold!?

Also, think about common mis-spellings.  For example, the “S” at the end of some names, such as SIMMONS, could be dropped, or a double letter shortened to one.  Modern typing errors often involve a key that is next to the correct on, so NUNN could become MUNN.

Think about letters that could easily look like another when viewing old handwriting.  One one of the census indexes I found that my BOTT ancestors had been indexed as BATT.

Genealogy, and in particular surname spellings, is never a straight-forward activity!  But this is what makes it so interesting – and also so rewarding when you finally discover your ancestor after doing some imaginative detective work.