1901 Census Page IDs

The 1901 Census Online Service provided by the PRO does not provide a direct pointer to the piece number and folio number where selected individuals may be found.
However, if you hover your cursor over the yellow "Image" icon, you will see some text containing a multi digit number at the bottom left of your screen. This is an internal representation of the page required - the Page ID.
Originally, this Page ID could be translated directly into a Piece and (approximate) Folio Number. However, in April 2003, this Page ID became encrypted and the original method (see below) now no longer worked. A good, but clumsy, work-around was invented, but even that has now been blocked - sorry. Not only is the Page ID encrypted, but it is different for every user, and changes on every search.

Original Method.

The following 2 links are to text files containing two tables, which open in a new window. They provide a translation of this Page ID to the piece number and approximate folio number where the required data may be found.
Piece number sequence - use to see project progress
Page ID sequence - use to identify your required page
You will, of course, need access to the relevant fiche or film in order to view the data.
Each row of the tables contains a Piece Number and Page ID (separated by commas).

How to use them is best explained using an example.
If you search the PRO Online Service for Henry Knaggs, aged 69, you will find him with the occupation "Tailor Retired", enumerated in Bristol.
Hovering the cursor over the yellow "Image" icon shows the Page ID 664042.
Now look in the second table to find the highest Page ID that is smaller than 664042.
You should find the row containing Page ID 663759 associated with Piece Number 2360.
Subtracting 663759 from 664042 gives 283.
Dividing by two gives 141.
Adding 1 or 2 gives 142 or 143. (This method is not absolutely precise.)
So, the required individual should be found at Piece Number RG 13/2360 at Folio Number 142 or 143.
In fact, you will find my great grandfather at Folio 142 Page 22.

If you can't find your person, look one or two pages each side.

WARNING In some piece numbers (notably for RN ships) there are blank folios that have not been filmed. In these cases the blank folios do not have PageIDs associated with them and this method will yield a folio number that is too small - keep looking.
For Royal Navy ships at sea (RG 13/5325 to /5335) I have built a separate index here.

Like all indexes and transcripts, these files are subject to human error - be careful.

Thanks to those of you who have helped with this project (especially James Heald).

I am told that the Page IDs are not visible on all browsers (notably Netscape Navigator). In this case you may be able to see them by first right-clicking on the icon and selecting "copy shortcut" from the menu, then pasting into a temporary word processing document.
I'm told that if you have a Mac, you can click on any non-link part of the results part of the screen and selecting View Source option, you will see a great jumble of text, hidden within will be the Page and Person IDs.

Several people have developed software to make the above tasks a little simpler and more convenient.
One from Stephen Miller is available from www.leedsindexers.co.uk/
An easy to use conversion tool with no software to download is available from Steve James at www.steeljam.co.uk/1901census/1901.html.

Person IDs.

Also, each person in the census has a unique Person ID associated with them. You can (or used to be able to) use these Person IDs to group the members of a household together in the order that they are found on the page. These Person IDs are found by RIGHT-clicking on the underlined name - if you can't see the number at the bottom of the screen, select "Properties" from the popup menu. These Person IDs are now encrypted in the same manner as the Page IDs.