I did some research on the US Tax law. It seems that if you make a $10 donation and get a T-shirt (which has a market value of $8), then you can deduct $2 of that donation from your taxes.

The Summary Fields extension can calculate the total amount of tax deductible contributions made by a single person over the course of the year by totaling the values in the civicrm_line_items table (and doing math with the non_deductible_amount field).

Now, I'm trying to figure out if the Summary Field extension can handle donations that come with premiums.

I created a premium - a T-shirt - and was pleased to see fields to record the market value which I filled in. I setup a "premiums" financial type - and set it to "Tax deductible".

I then setup a contribution page and added the T-shirt premium. When I make the donation and select the premium... I get a single entry in the civicrm_line_items table with a financial type of "donation" (which is what the contribution page is configured to use) and non_deductible_amount of 0. I was hoping to get a financial type of "Premium" and a non_deductible_amount of 8.

Is my expectation wrong? Since this might be different in different legal jurisdictions, perhaps this calculation should be done in an extension instead?

  • It looks to me like the contribution itself has the correct non-deductible amount, but the line item does not. So if you can use the contribution instead of the line item, this should work for you. I imagine this was just never implemented for line items and unfortunately there is not yet any mechanism to enforce consistency of deductible amount between line items and contributions.
    – Lars SG
    Jul 29, 2023 at 2:44
  • Thank you! This is really helpful. I did not notice that the correct non-deductible amount was recorded in the contribution field.
    – Jamie
    Jul 31, 2023 at 13:50

1 Answer 1


I'm not sure if this is a full answer but here's what I know about it:

Civi is inconsistent regarding non-deductible amounts. I don't remember seeing a spec where it was written out how it should work in various situations. Note also there are conflicting/ambiguous non-deductible fields on both the line item and the contribution, as well as potentially ambiguous financial types on the contribution and line items. And if you edit the contribution the non-deductible is not always in sync after. I personally don't think it's reliable to rely on those fields.

  • Thi is also helpful - and I think the correct answer. However, given that the non-deductible amount is at least correct in the contribution record it gives me hope that we can at least slowly fix this problem until it is more reliable. If I have time I will try to at least patch the line item table on initial creation.
    – Jamie
    Jul 31, 2023 at 13:52

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