Trying to find the right reference number when you want to request documents from the Library and Archives Canada (LAC) collection can be a little daunting to a newcomer and sometimes even to the seasoned researcher. With titles such as MIKAN number, archival reference no., former archival reference no., related control no., and other system control no., it can be difficult to know which number is required to place your request.
In general, the complete archival reference information that you need to request documents for consultation (or reproduction) can be found in the “Conditions of access” section of the online description for files, items and accessions, and should be read from bottom to top.

A sample record description in the Library and Archives Canada Archives Search database. Note the conditions of access in the right column.
You will need to make note of the following information (if available), in the order indicated (1 to 6), in addition to the document title (located at the top of the description page):
- Archival Reference number – e.g., R112
- Former archival reference no. – e.g., RG, MG, LMS, MUS. It is also important to transcribe all of the information that follows the letter identification.
- An accession or BAN number – e.g., 2003-00459-9
- A volume or box number—without a volume or box number, nothing can be ordered.
- File no. (creator) or Item no. (creator)
- File title
For the preceding example the following information would be needed for document retrieval:
RG45, Volume 209, File no. 1147
Here are other examples of reference numbers organized by media type.
Please note that the “Conditions of access” section also contains important information on access restrictions (identified by an access code) that apply to the records described and that indicate whether documents may or may not be freely consulted for research and reproduction purposes. For more information about access codes, please consult the following blog posts: Introduction and Part II.
Important considerations:
- Retrieval times for archival documents are between 36 and 48 hours as the documents are kept offsite and must be brought to 395 Wellington for viewing.
- Pay close attention to the restriction codes on the documents, which may require you to provide additional information if the files happen to be restricted.
- Some documents have already been microfilmed and are available for immediate viewing in the consultation room. If you see a record with a microfilm reel number, you can go directly to the microfilm room and pull the reel from the shelf for viewing.
- In addition, some microfilmed documents have been digitized through our collaboration with Canadiana and are available on the Héritage website.
If all else fails, feel free to ask the Orientation or Consultation staff for help to find the correct reference number, or complete the Ask Us a Question form.