Use the Underdog promo code TOPACTION to unlock a $75 welcome bonus on Thursday, December 18, 2025. Right now, you can claim this sign-up offer and submit a $5 lineup using picks from Thursday Night Football. Win or lose, you get $75 in bonus entries.
Simply enter the Underdog promo code TOPACTION or click the link below to claim this offer. Then submit your first lineup using NFL picks for tonight's game.
| Underdog Promo Code | Underdog Sign-Up Bonus | Underdog States Available |
|---|---|---|
| Underdog Promo Code TOPACTION | Play $5, Get $75 in Bonus Entries | AL, AK, AR, CA, DC, FL, GA, IL, IN, KS, ME, MS, MN, NE, NM, NC, ND, OK, OR, RI, SC, SD, TX, VT, VA, UT, WI, WY |
The marquee matchup tonight is Rams vs. Seahawks on TNF, kicking off at 8:15 p.m. ET. It promises to be one of the most exciting NFL games of the season, making it the perfect time to create your DFS lineup.
Don’t miss your chance—use the Underdog promo code TOPACTION today and claim your $75 welcome bonus before Thursday Night Football.
Underdog Fantasy Promo Code TOPACTION: Rams vs. Seahawks Lineup Example
Register now using the Underdog Fantasy promo code TOPACTION and submit a $5 lineup featuring picks from the Rams vs. Seahawks game. Need more convincing? DFS expert Nick Goodling explains why this welcome offer is too good to miss.
“This is one of the easiest ways for NFL fans to jump into daily fantasy and get a ton of value right out of the gate. Don’t sleep on this, claim your bonus and start building your lineup today.” – Nick Goodling
Once you complete registration, it’s time to submit your first lineup. Select “Higher” or “Lower” on a player projection to add a pick. You can include up to eight picks in your lineup, with a maximum payout of 120x.
If your lineup has three or more picks, you choose between Standard and Flex entries. The Standard entry offers the largest payout, but only with a perfect lineup. Flex entries offer a smaller payout for a perfect lineup but still allow a profit or the return of your stake if one pick loses.
Sign up today with the Underdog promo code TOPACTION and submit a $5 NFL lineup. Win or lose, you get $75 in bonus entries for the Rams vs. Seahawks Thursday Night Football matchup.
| Player | Team | Pick |
|---|---|---|
| Jaxon Smith-Njigba | Seattle Seahawks | Higher Than 91.5 Receiving Yards |
| Matthew Stafford | Los Angeles Rams | Higher Than 237.5 Passing Yards |
| Zach Charbonnet | Seattle Seahawks | Lower Than 35.5 Rushing Yards |
How to Sign Up for Underdog Today
Follow the steps below to claim the Underdog promo code TOPACTION and make your first deposit and lineup on Thursday:
- Step 1: Use the Underdog promo code TOPACTION sign-up module on this page to download the Underdog app.
- Step 2: Create a username and password.
- Step 3: Fill in your email, date of birth, and all other required personal information to create a new Underdog account.
- Step 4: Enter the Underdog Fantasy promo code TOPACTION for a play $5, get $75 in bonus entries offer.
- Step 5: Agree to the Underdog Terms of Use and Privacy Policy. Confirm you are at least 18 years old (19+ in Alabama/Nebraska, 21+ in Massachusetts/Arizona).
- Step 6: Click "Sign Up."
- Step 7: Make your first deposit of $10+.
- Step 8: Create your first entry at Underdog with picks from the NFL or any other sport.
Claim Your Underdog Promo Code Holiday Bonuses 🎁🚀
Now that your Underdog account is ready, it’s time to put your promo code to work. Underdog is rolling out a series of holiday boosts and special picks that you can use to maximize your entries and make your season’s picks even more rewarding.
Here’s the schedule:
12/18
- Jake Paul Boxing Fight: 50% restricted boost live 🚀
- 50% sitewide unrestricted boost 🚀
12/19
- Jake Paul Fight 50% Boost ENDS 🚀
- Josh Allen sitewide Gimme Pick goes live 🎁
12/20
- 40% sitewide unrestricted boost
- 40% NFL restricted boost 🚀
12/21
- Josh Allen sitewide Gimme Pick ENDS 🎁
- 40% NFL restricted boost 🚀
- Witching Hour event
12/24 – Unwrap Your Gift 🎁
12/25 – NFL sitewide Gimme Pick (live after MNF on 12/22 tipoff) 🎁
12/27 – Unwrap Your Gift 🎁
12/29 – 50% sitewide unrestricted boost 🚀
12/31 – Unwrap Your Gift 🎁
Use the Underdog promo code TOPACTION to unlock these boosts and special picks while they’re live. Keep an eye on the schedule so you don’t miss a chance to maximize your account.
Must be 18+ (19+ in AL, NE; 19+ in CO for some games; 21+ in AZ, MA, and VA) and present in a state where Underdog Fantasy operates. Terms apply. See assets.underdogfantasy.com/web/PlayandGetTerms_DFS_.html for details. Offer not valid in MD, MI, NJ, NY, OH, and PA. Concerned with your play? Call 1-800-GAMBLER or visit www.ncpgambling.org; NY: Call the 24/7 HOPEline at 1-877-8-HOPENY or Text HOPENY (467369).
