I received a reply:
We may hold records related to pedlar's certificates. All of our records are listed and described in our online catalogue. To find records you need to search our catalogue using dates and words likely to match catalogue descriptions. Catalogue descriptions vary hugely, from the very brief (sometimes just a word or two) to detailed descriptions of multiple paragraphs and hundreds of words. Usually, though, they are a line or two of text. A catalogue search does not search the content of the record itself, only the description of the record written for the catalogue. For more advice on searching effectively, read our catalogue help pages or our blogs on using the catalogue.
I have searched our catalogue for records using 'Pedlars certificates' (
https://discovery.nationalarchives.gov.uk/results/r?_q=Pedlars%20certificates&_ps=60) as search terms. You can view the results of the search here and try some similar searches yourself. It looks as though these records are mainly 'held by' local and county record offices. You can use our find an archive tool to locate a relevant archive in the area of interest to your research.
The catalogue also provides details of where each record is held, whether it is here or at one of the hundreds of other archives across the UK whose records are also listed in the catalogue (keep an eye on the ‘Held by’ line for each catalogue search result). If the record is held at another archive you will need to contact that archive directly to find out how you can see their records. If the record is held at The National Archives, the full description (which you arrive at by clicking on its catalogue title) will indicate your ordering and viewing options, including whether the record can be seen online. Online records can be viewed and downloaded either directly from the catalogue or from the websites of our commercial partners (there will usually be a subscription cost to download the record from these sites). Many of our records, however, are not viewable online and for these you can order digital copies to be sent to you by clicking on the 'Request a copy' link contained within the catalogue description (you will need to register your details with us before you request copies).
The Hawkers I am looking for were in Wales. Only one record related to Wales, so I will contact the Archives in Aberystwyth. I posted all of the reply, as it might help others.
