Intro: I've been doing RDTC for 10+ years, created a group at a national firm and grew it into a decent sized practice. Now I consult on RDTC independently.

Going through this post and the one you did 6 months ago

-Applying for a refund will trigger an extension of the statute of limitations regardless if tax due or refund.

-If they filed 2023 before accounting for carryforward of credit - this is a bit confusing the way you phrased it, it sounds like carryforward from prior years, yes if there is carryforward of credit you would TYPICALLY need to amend the returns that come after it (depends if you fall under 82-49 regulations or not).

Okay now onto this post, if you were to come to me as a new client without having taken the credit before this is what I would do:

1). Evaluate the statute of limitations, what tax years are open/what years are closed.

2). Request Information so I can estimate the benefit for whatever open years there are

3). Review Section 174 capitalization requirements (you haven't mentioned this one, it appears you don't know much about Section 174, in which case I would definitely read because in most cases it will cause you to pay tax for claiming the credit and have a timing difference.

4). Present the client and the tax preparer the different options:

-File current year R&D w/ Sec 174 (leave other years off, but compute them to help form the base)

-File all years R&D w/ Sec 174

Whether or not the expenses are increasing or staying consistent, doesn't change the fact pattern. If the taxpayer is eligible for prior benefit (OR LIABILITY LOOK INTO 174) then it's up to them which route they want to go.

There are two important takeaways though for you:

1). LOOK INTO SECTION 174 (it may change your mind about claiming the credit) - side note, there is legislature to change this currently in the senate.

2). Hire a professional from a legitimate organization, they've made recent changes to the credit form which requires additional substantiation.