# Modeling alternate ids in hub - BKCC? **URL:** \ **Category:** Data Vault 2.0\ **Tags:** business-key, hub\ **Created:** [June 29, 2022, 7:45am UTC](https://forum.data-community.org/t/modeling-alternate-ids-in-hub-bkcc/349 "2022-06-29T07:45:23Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![malcolmhaar](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.data-community.org/malcolmhaar/32/126_2.png) [@malcolmhaar](https://forum.data-community.org/u/malcolmhaar)\ **Post date:** [June 29, 2022, 7:45am UTC](https://forum.data-community.org/t/modeling-alternate-ids-in-hub-bkcc/349/1 "2022-06-29T07:45:23Z")
Let’s say I’m building a Person hub and I get a mix of ids from sources. Some of the IDs are source-specific (i.e. meaningful only within that source). Others are meaningful across sources (e.g. drivers license number, government id number). For example: ![image](https://europe1.discourse-cdn.com/flex013/uploads/datavaultusergroup/original/1X/d88a6ecdfb9276c5f143550915b47c19b83593da.png) I think the following are correct, with respect to Data Vault modeling: 1. All of the ids should be in a single Person hub 2. The source-specific ids should use a BKCC to keep the ids from mixing across sources For the cross-source ids (e.g. drivers license, government id number) I see two options: 1. Use a BKCC for each type of cross-source id (e.g. “DL”, “GOVID”), being careful not to overlap any source BKCC identifiers with these BKCCs. 2. Use a concatenated business key, e.g. “GOVID-123456” with no BKCC Are these reasonable options? Is option 1 within the “spirit” of a BKCC? Are there better options? Thanks for guiding a Data Vault newbie 🙂 ---
**Author:** ![patrickcuba](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.data-community.org/patrickcuba/32/19_2.png) [@patrickcuba](https://forum.data-community.org/u/patrickcuba)\ **Post date:** [June 30, 2022, 1:22am UTC](https://forum.data-community.org/t/modeling-alternate-ids-in-hub-bkcc/349/2 "2022-06-30T01:22:02Z")
Keep in mind mate, and as I have said before, BKCC is **not** source driven. Only use BKCC sparingly when there _could_ be a clash. The moment you default BKCC to source then you will be building a convoluted mess, source-system vault, _ala_ fake vault. **Never** concatenate business keys, you’ve modified data in this regard > **[A Rose by any other name… wait.. is it still the same Rose?](https://medium.com/snowflake/a-rose-by-any-other-name-wait-is-it-still-the-same-rose-3a6202d1aecd)** > > The title and subject of this discussion is the contextual nature of business keys, keys are the immutable value that represents a thing… ---
**Author:** ![malcolmhaar](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.data-community.org/malcolmhaar/32/126_2.png) [@malcolmhaar](https://forum.data-community.org/u/malcolmhaar)\ **Post date:** [June 30, 2022, 1:51am UTC](https://forum.data-community.org/t/modeling-alternate-ids-in-hub-bkcc/349/3 "2022-06-30T01:51:24Z")
@patrickcuba Thanks for the reply. I do understand that it’s not appropriate to default a BKCC to a source as a general rule, as then you forego the ability to passively integrate when sources share a common business key. And I have read your Rose article 🙂 In my case, it _is_ possible for XYZ’s keys to overlap with ABCs as these are separate systems generating the IDs. I don’t see how it’s possible to have anything but a source-system id for these ids. For the Driver’s License and Government ID I do want them to integrate as they are the same across sources. However a Driver’s License and Government ID could in theory overlap, as I don’t have any guarantee as to their formats. ---
**Author:** ![patrickcuba](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.data-community.org/patrickcuba/32/19_2.png) [@patrickcuba](https://forum.data-community.org/u/patrickcuba)\ **Post date:** [June 30, 2022, 3:23am UTC](https://forum.data-community.org/t/modeling-alternate-ids-in-hub-bkcc/349/4 "2022-06-30T03:23:06Z")
Thats good, The general advice on government issued ids is that they are **not** used as business keys by legislation, at least in Australia this action is not allowed and are anyway something that could be considered PII and should be locked away in a PII satellite. For reference: [Chapter 9: APP 9 — Adoption, use or disclosure of government related identifiers - Home](https://www.oaic.gov.au/privacy/australian-privacy-principles-guidelines/chapter-9-app-9-adoption-use-or-disclosure-of-government-related-identifiers) ---
**Author:** ![RhysHanscombe](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.data-community.org/rhyshanscombe/32/394_2.png) [@RhysHanscombe](https://forum.data-community.org/u/RhysHanscombe)\ **Post date:** [December 1, 2025, 2:29pm UTC](https://forum.data-community.org/t/modeling-alternate-ids-in-hub-bkcc/349/5 "2025-12-01T14:29:49Z")