My audit shop is brainstorming better alternatives for project coding. We currently number all project types (Financial Operations, IT, Control Self-Assessment, Special Project, Investigation) by date and number based on the order they appear in our audit plan. For example, 50 projects labeled 2024-01 through 2024-50. All additional items throughout the year are subsequently coded based on order of addition.  Wondering what's working for everyone else? Are project types differentiated within project codes? Does project numbering go from 1-X per project type or is project numbering consecutive for all project types? 

I agree with the others that your method sounds like it would be difficult to scale.

 We use Oracle Project Costing to track our project costs. Our actual project number is sequential but starts with a prefix, such as ACQ for an acquisition project type. The various project types break down by the nature of the project tasks included with that type of project (New Builds, IT Capital, Facilities, Grants, Acquisitions, Initiatives, Self-Development, Insurance).

Each project type has best practices for project name nomenclature. All start with the fiscal year the budget is approved for, all include the location number the project relates to (unless it is a company-wide project). Other additional values that could be included in the name include a more granular budget category, the grant name, the named storm an insurance loss related to, etc.

Initials of the vendor project and a unique string of numbers. 

Your method works but I do not think it is a scalable process to base the ID on date because if something happens to a project and you need to create a second project ID with the same vendor, it may lead to a longer ID string to differentiate it from the original. If you need the date in there then I would advocate, initials, year followed by random unique ID numbers. I say it really depends on the scale of your company and what the goal is. But I would be concerned that the current outline of your project coding would not work on a larger scale. Hope this helps.

We use a combination of the fiscal year the project was approved and an acronym of the project name. e.g. T24-PRCJ. Including the approval FY allows us to identify projects that need to be reviewed especially if they are not moving fast enough or are on hold for various reasons. 

In our organization, project identification is not specifically classified to a particular solution or timeframe when the project will run; a generic sequential number is assigned, like PRJ00101. 
The rationale is that projects get moved paused, cancelled and amended (for scope and time) at various times and thus using any form of reference beyond a number may mislead the audience referring to it.