A lot — but it’s hard to pin a single, exact number. Large corporations routinely spend tens of millions each year (collectively hundreds of millions) on lobbying that targets tax rules, and wealthy individuals and dark-money networks add substantially through outside spending, think-tank grants, PACs and grassroots campaigns.

Because lobbying filings don’t always assign dollars to specific issues, researchers use proxy measures (who registers on “tax” issues, how many lobbyists, and total lobbying budgets of those clients) to estimate scale.

Below I explain what the data show, who the major players are, how rich people inject money into tax politics, and why precise totals are difficult to produce. 

1) Why there isn’t one neat dollar figure

Federal lobbying filings (the Senate’s Lobbying Disclosure Act reports) list how much each client spent on lobbying overall, and they let filers name issue areas (e.g., “taxes”). But the filings do not require lobbyists to break a client’s dollar total down by specific issue. That means we can count how many organizations and lobbyists worked on tax issues, and we can see how much those organizations spent in total — but we cannot reliably sum a single, audited national “tax-lobbying” dollar figure from the filings alone. OpenSecrets therefore reports client totals and issue tags rather than an itemized dollar amount targeted exclusively at tax policy. 

2) Scale and scale indicators (what the data do show)

• Total federal lobbying reached roughly $4–4.5 billion per year recently (2023–2024), so tax lobbying is a slice of a multi-billion dollar market. 
• Clients on “tax”: In 2024 OpenSecrets identified ~11,700 distinct clients who lobbied on taxes (clients can be companies, trade groups, or nonprofits). That’s a huge footprint — thousands of organizations are actively engaged on tax issues. 
• Lobbyist manpower: Citizens for Tax Justice found that in 2024 about 6,100 federal lobbyists worked on tax issues — nearly half of registered lobbyists that year — equal to ~11 tax lobbyists for every member of Congress. That illustrates intensity even if it’s not a dollar total. 

3) Who spends the most (examples)

Because issue-by-issue dollars aren’t itemized, researchers point to the big lobbying spenders who also list “taxes” as an issue:

• U.S. Chamber of Commerce — one of the largest single lobbying budgets (about $69.6 million in 2023); it also runs large tax campaigns and deploys lots of tax lobbyists. 
• Trade groups and corporate giants — Business Roundtable, Big Tech (Google/Alphabet, Microsoft, Meta), major banks, telecoms, pharmaceutical firms, energy companies, FedEx, Verizon, Intuit, etc., all register tax lobbying among their issues. OpenSecrets shows many of these groups among the top clients who flagged “taxes.” 
• Koch network / Americans for Prosperity — a wealthy-donor network that spends both on direct lobbying and large outside spending/drives grassroots campaigns in support of tax cuts; Koch Industries alone reported $11.26M in federal lobbying in 2024 (not all on taxes). 

Taken together, the top corporate and trade clients that explicitly lobby on taxes typically have annual lobbying budgets in the tens of millions; the cumulative effect across hundreds or thousands of such clients means hundreds of millions — plausibly a low-to-mid hundreds of millions of dollars annually — are dedicated (in part) to shaping tax policy, even if a clean line-item can’t be drawn. (That is a reasoned, conservative estimate based on client totals and issue registrations.) 

4) How wealthy individuals influence tax policy (beyond direct lobbying)

Wealthy people rarely “lobby” in the LDA sense themselves. Instead they influence tax policy by:

• Funding dark-money groups and 501(c) organizations that run ad campaigns, grassroots mobilization, and policy research (the Brennan Center reports record dark-money spending — $1.9 billion in the 2024 cycle). Those groups then push or block tax proposals. 

• Backing think tanks and scholarly projects that produce sympathetic tax-policy research and expert testimony.

• Donating to Super PACs and outside spending groups that sway election outcomes and hence the composition of tax-writing committees. (Examples: Koch network activity around tax campaigns; donors use hybrid PACs, 501(c)(4)s and foundations to underwrite tax messaging.) 

That means even when wealthy individuals aren’t listed as “lobbyists,” they amplify corporate lobbying by underwriting the ecosystem that changes public opinion and the political environment.

5) Concrete evidence of influence

• Lobbying spikes around major tax fights. During the drafting of the 2017 Tax Cuts and Jobs Act, corporate lobbying surged in late-2017 as companies, law firms and trade groups rushed to shape final language and carveouts. Journalists and watchdogs documented that spike. 

• Recent tax debates (Wyden-Smith negotiations, 2024–25 tax packages) similarly produced a lobbying boom — Reuters/Bloomberg reporting shows K Street revenues jump when tax bills were in play. This demonstrates that where there’s money on the table, corporations and wealthy networks mobilize big resources fast. 

6) Why this matters

Tax law determines how much corporations and wealthy people pay, and how business models are rewarded (carried interest, pass-throughs, depreciation rules, international taxation). Lobbying shapes deductions, credits, timing, and enforcement. The raw presence of thousands of tax lobbyists, high lobbying budgets among top clients, and massive dark-money outside spending means policy choices about tax fairness, revenue, and distribution are heavily contested — and that contest is funded by powerful private money. 

7) Bottom line & transparency caveat

• Bottom line: Large corporations spend tens of millions each (and collectively likely hundreds of millions annually) on lobbying that affects tax policy; wealthy individuals and dark-money networks add hundreds of millions more in outside spending and influence. The total ecosystem around tax politics therefore runs well into the high-hundreds-of-millions (and arguably into the low billions, counting all related outside spending and think-tank financing). 

• Caveat: an exact, single number is impossible to calculate from public filings because clients report overall lobby budgets, not dollars per issue; researchers therefore rely on proxies (issue tags, number of lobbyists, client totals), as cited above.