The spellings that swapped places

In 2017, 725 American boys were called Philip. Another 725 were called Phillip. Not roughly the same. The same.

It was not always a draw. Philip was the bigger spelling every year from 1880 to 1959. In 1960 Phillip went past it, 27.9 boys in every 10,000 to 25.5, and stayed in front for the next 56 years. Then in 2016 Philip went back ahead, 435th in the rankings to Phillip's 437th, and it has been ahead every year since. In 2025 it is 528th and Phillip is 651st.

So we went looking for every name like it. Old names, two spellings, both of them in real use. There are 25, and on 16 of them American parents changed which spelling came first.

How we counted

We used the American records for every year from 1880 to 2008, and the full files for 2010 and 2017. A name is on our list when it has two or more spellings said the same way, when it had its best year in the last century at one baby in 200 or better, and when the second spelling had at least 30% of the name at some point. That last test is the one that matters. It keeps out names where one spelling was never in any danger, like Rachel and Rachael.

We left out pet forms like Kathy and Cathy or Terri and Terry, because they come in half a dozen endings each and deserve an article of their own. We left out names said differently, like Deborah and Debra or Caroline and Carolyn. And we only count a change of lead when the new spelling stays in front for five years running, so a single odd year does not count.

The 25 names

Here is every one, with the spelling that led first, when that changed, and the 2017 count for each spelling.

Sixteen of the 25 changed leader at least once. Three changed back: Anne, Philip and Marcia. Nine never changed at all, and one of those nine is only just holding on. Erica has led Erika since the name took off in the late 1960s, but in 2017 it was 325 Ericas to 365 Erikas, which is too close and too recent to call a change.

We looked for a rule about which spelling wins, and there is not one. Of the 17 changes in the table, the shorter spelling won six, the longer one won five, and six were between spellings of the same length. Steven beat Stephen, but Phillip beat Philip before losing to it again. Alan dropped a letter and Allison added one. What there is, is a pattern in how the changes happened. There are two kinds.

The new spelling that came with the boom

Stephen was the spelling for seventy years. In 1940 it went to 37 boys in every 10,000, and Steven to 13. Then the name took off, and almost all of the growth went to Steven. By 1950 Steven was on 128 and Stephen on 113. By 1955 it was 181 to 106.

And then it settled. Since 1960 Steven has had between 61% and 68% of the name in every decade we can measure, and in 2017 it was 2,148 boys to 1,321. That is two Stevens to every Stephen, for sixty years. Both have fallen a long way since, and Steven is 271st in America now and Stephen 383rd, but the order has not moved.

Nine of the changes on our list look like this. The new spelling at least doubled in the ten years before it took over, while the name as a whole was climbing: Alan in 1943, Steven in 1950, Teresa in 1951, Michelle in 1956, Allison in 1963, Derek in 1970, Kristen in 1973, Kaitlyn in 1992 and Hailey in 2001. Michelle went from 4.7 girls in every 10,000 to 25.9 in those ten years. Teresa went from 5.8 to 33.6. Kaitlyn was not in the top 1,000 in 1982 and was on 37.3 by 1992. In eight of the nine the name's best year was still to come, and most of the parents arriving chose the new spelling. Hailey is the odd one: it passed Haley in 2001, the year after the name peaked.

The spelling that won by standing still

Now look at Philip. In the ten years before 1960, Phillip did not grow at all. It went from 27.8 boys in every 10,000 to 27.9. Philip fell from 33.4 to 25.5, and that was enough. Phillip did not win. Philip lost.

The other seven changes are like that. In the ten years before it took over, the new spelling grew by a tenth at most, and four of them shrank. The old spelling just fell faster, by between a quarter and three fifths: Marian in 1953, Phillip in 1960, Marsha in 1969, Katherine in 1973, Anne in 1978, Sean in 1981 and Bryan in 2006. These are names on the way out, and the spelling that was left standing is the one that fell more slowly.

Bryan is the clearest case. In 1973 Brian went to 221 boys in every 10,000 and Bryan to 44. That is five to one. Over the next 33 years Brian fell by six sevenths and Bryan by a third, and in 2006 they met at about 30 each. Bryan has been a nose in front in most years since. In 2017 it was 1,827 boys to 1,763, and on the rankings the lead has changed hands six times since 2018. Brian was ahead in 2019, 2022 and 2024, Bryan in the other years. In 2025 Bryan is 336th and Brian 339th. It is the closest contest on the list, and it is still going.

Catherine is the slowest. It led from the start of the records, and it was 83 girls in every 10,000 in 1914, the name's best year, to Katherine's 46. It took until 1973 for Katherine to get past, at 28.5 to 27.5, and by then the name had been falling for almost sixty years. Anne had changed once before. Ann overtook it in 1894 and kept the lead for 84 years, until Anne went back in front in 1978.

Sean is the other boys' name in this group. Shawn was the spelling in front when the name arrived in the late 1950s. Both fell after the name's best year in 1971, Shawn faster, and Sean took over in 1981, at 47.8 to 38.0. And Marcia is the one that came back. Marsha led from 1969, and by 1984 Marcia was in front again, though by then there were fewer than two of either in every 10,000 girls.

Which spelling Britain uses

Our British records cover the babies born in England and Wales in 2024 and 2025. That means we cannot tell you when Britain switched spellings, or whether it ever did. We can tell you which spelling British parents pick now, and whether it is the same one American parents pick.

Fifteen of the 25 names were given to 50 or more babies in England and Wales in 2025. On nine of them Britain agrees with America. On six it does not.

Look at the first three. Stephen, Catherine and Caitlin are the spellings America started with and gave up, in 1950, 1973 and 1992. Britain still leads with all three. The numbers are small, because these names are rare here now, so we checked them against 2024 as well. Stephen led Steven 57 to 41 that year too, and Caitlin led the next spelling 64 to 22. Catherine and Katherine were level, 66 each, so treat that one as a lean rather than a result. Erica makes a fourth, if you count it. Britain leads with it 67 to 39, while in America the Erikas have just caught up.

The other two are Britain's own. Robyn went to 611 girls in England and Wales in 2025 and Robin to 186. Robyn is 76th here. In America Robin has always led, and in 2017 it was 252 girls to 234, so it is not that America never heard of the y. And Sara leads Sarah here, 427 to 371 in 2025 and 476 to 375 in 2024. Sara is 110th and Sarah 131st. In America Sarah has led every year since 1880, and in 2025 it is 90th to Sara's 198th. The official files cannot tell us how each family says Sara, and some will say it differently, so read that one with care.

There is one exception going the other way. Haley was America's spelling until Hailey passed it in 2001. In England and Wales in 2025 it went to four girls. Britain went with Hailey, 115, and its second spelling is Hayley, 83, which in America is the smallest of the three.

And one name is not on our list because America never argued about it. Lawrence went to 579 American boys in 2017 and Laurence to 72. In England and Wales in 2025 it was Laurence 101, Lawrence 71, and 106 to 66 the year before. We were hoping to do the same for Geoffrey, but America never had a contest there either (Geoffrey's best year was 8.6 boys in every 10,000, against 166 for Jeffrey in 1966), and in England and Wales in 2025 there were 15 Jeffreys, 9 Geoffreys and 6 Jefferys. That is too few to say anything, and our British records do not go back to the years when any of them were common. The same goes the other way for Eric, which has never been behind in either country. In 2017 it went to 2,757 American boys against 1,428 for Erick and 895 for Erik, and in England and Wales in 2025 it was 300 against 99 and 27.

What it means for you

If you are choosing between two spellings of an old name, the one in front today is not guaranteed to be in front when your child is grown up. Sixteen of these 25 changed at least once. But look at how they changed. When a name is climbing, the new spelling tends to win. When a name is on its way out, the spelling that wins is the one parents let go of more slowly.

And if you are in Britain and worried that a spelling looks American, check which way round it is. Of the six names where the two countries disagree, in three, and four if you count Erica, Britain is the one that kept the spelling America started with. Stephen, Catherine and Caitlin are still the British way round.