How can allocate tax to different products using tags?

Unfortunately, there isn't a direct way to tag or allocate tax to specific products using AWS tags. Tax is typically considered part of the unallocatable spend in AWS, which cannot be tagged in advance. However, there are some strategies you can use to allocate tax and other untaggable costs across your products:

1. Proportional Allocation: You can allocate tax proportionally based on the tagged costs of each product. For example, if Product A accounts for 60% of your tagged costs and Product B accounts for 40%, you could allocate the tax in the same proportion.

2. Cost Categories: AWS Cost Categories allow you to group accounts and tags within an AWS Organization. You can create cost categories that include both your tagged resources and a proportion of unallocated costs like tax. This provides a more comprehensive view of costs related to each product or category.

3. Custom Reports: Use AWS Cost and Usage Report or AWS Cost Explorer to export your cost data, including both tagged and untagged costs. You can then use external tools or spreadsheets to manually allocate the tax based on your preferred methodology.

4. FinOps Practices: Implement FinOps (Financial Operations) practices in your organization. This might involve assigning a financial management specialist to work with engineering teams to ensure comprehensive cost allocation, including tax and other unallocatable spend.

While these methods don't allow for direct tagging of tax, they can help you achieve a more accurate allocation of all costs, including tax, across your products. Remember to regularly review and update your tagging strategy to minimize untagged resources and improve overall cost visibility.

Sources
Building a cost allocation strategy - Best Practices for Tagging AWS Resources
Tags for cost allocation and financial management - Best Practices for Tagging AWS Resources