That's not how it works.  Taking the standard deduction doesn't free up the 'unused' charitable to carryover.

Oh - I forgot that $ 300/600? you got if you weren't itemizing.  There's a box to check somewhere on the itemized deductions 'page'.  But I'm a Lacertian - ya' need a PS person to stop by with the specifics

Ok I thought you could take the standard deduction and still take a small (few hundred) dollars of charitable contributions? 

See my edit...

That went away after 2021. it was a  temporary provision of the COVID-19 relief legislation.

The OP did mention 2020.....

Were they cash contributions?

I think you need to enter it on the worksheet on Schedule A where you list the charity name and amount, not directly on the Schedule A line.

I think that for at least one of the years you had to enter it directly on the 1040 Worksheet (maybe both Schedule A and the 1040 worksheet; I think there was a mini-worksheet on the 1040 Worksheet).

Sorry, missed the 2020, as a side note you only have until 5/17/24 to get a refund from 2020. You enter charitable donations ($300/$150 MFS) directly on 1040/1040SR worksheet line 10b. note for 2020 everyone could only take $300 per return except MFS was only $150.

Just wondering are you going to charge them for the extra work/research and figuring this out? If they are in a 15% bracket and it is a $300 amount, than they saved a whopping $45 in tax.

@PATAX say you complete a retrun.. two months later client contacts you with an amended 1099-DIV.  the only change was they allocated more to qualfied dividends.. results in $ 122 add't refund on the 1040X if you one is filed.. would you charge for that?  that is what happened to me yesterday.

@Jim-from-Ohio yes charge a reasonable fee for that. It was not your fault why should you do it for free. Years ago I would not charge clients for situations like that. Not anymore. If it's not my fault then I charge them. If they don't like it then they can leave. 

Or you tell them that the IRS will pickup the change within 16 months of the April 15 filing date, and they might correct the refund themselves.

Although they don't usually calculate correctly when there are Qualified Divs.

@PATAX ok.. emailed the client. told them i could do it and gave them the modest results and my small fee.. they said go with it.. took me about six minutes total including emails back and forth and 1040-X prep

@Jim-from-Ohio good job.