A Scan Jammer interrupts the frequency authorities use to detect illegal cargo, cutting your odds of getting caught at a contraband scan. Here is how to buy, equip, and actually make one work.
What Is a Scan Jammer and How Does It Work?
A Scan Jammer—sometimes called a signal jammer or scanner jammer—is a ship module that messes with the frequencies system authorities use to scan your ship. When you get pulled into a contraband scan, the jammer makes it harder for their scanners to read what's actually in your hold, giving you a percentage chance that illegal goods slip through unnoticed. It's not a cloak, and it won't stop the scan from happening—it just makes the scan less accurate.
What actually trips up most new smugglers isn't the jammer itself — it's where the contraband happens to be sitting. A Scan Jammer only hides illegal goods that are stored in your ship's inventory. If you're personally carrying Aurora, stolen organs, or any other restricted item on your character, the jammer does nothing at all, and your evasion basically drops to 0%. It's an easy mistake to make, since the game gives you zero warning before you undock. I found out the annoying way after a run through Cheyenne with a pocket full of contraband and a perfectly good jammer bolted to my hull — the scan went through like I wasn't even equipped. So before you jump into a patrolled system, open your inventory and move every restricted item into the ship's cargo hold. Do that, and the jammer finally has something to protect.
A Scan Jammer only gets you so far on its own — it's one piece of a larger smuggling setup. The real payoff comes when you pair it with a Shielded Cargo Hold, which hides some of your cargo from scanners by itself, before the jammer even factors in. And you don't need to stack these things: one shielded cargo module does the job, so plastering them all over your ship just adds dead weight for nothing. Here's a simple way to think about it — the jammer is your active layer, the shielded hold is your passive layer, and the Deception skill sits on top of both as a third modifier. Get all three working together and you're giving yourself the best possible odds of slipping contraband past a scan.
How to Equip a Scan Jammer to Your Ship
Plenty of first-time shipbuilders get tripped up here: you can't just slap a Scan Jammer onto any stretch of open hull. The module needs a proper mounting surface, and in Starfield that means an Equipment Plate from the Structural tab in the ship builder. Without that plate, the jammer simply won't snap to your ship — it doesn't matter how much bare hull you've got staring back at you or how many times you drag the thing into place. It's an easy step to overlook, especially if you're used to modules that attach directly, but once the plate is down, the jammer drops right on top of it and you're good to go.
This is the exact sequence I run through at any ship services technician, and once you know where everything lives, it takes about a minute. Open the ship builder, then drop an Equipment Plate from the Structural tab anywhere on your ship. It's just a mounting point, so you can put it wherever it fits. From there, switch over to the Equipment tab, pick your Scan Jammer, and place it right on top of that plate. That's the whole install. Once the module is attached, its evasion bonus kicks in automatically at every contraband scan. No activation step, no hotkey, no menu toggle. In other words, you don't have to "turn it on" before jumping into a guarded system. The jammer just does its thing in the background, and the game checks its evasion percentage the second an authority scan begins.
Here's a detail a lot of new smugglers overlook: every Equipment Plate and Scan Jammer you bolt on adds mass, and mass is what kills your mobility and jump range. On a purpose-built smuggling runner, that's rarely a problem. You've probably stripped the weapons and kept the frame lean, so a few extra units barely register. But if your ship is already hauling heavy weapon batteries, a bulky reactor, and a large shielded cargo hold, the extra weight starts to add up. Mobility falls off, grav jump range gets shorter, and the whole ship feels sluggish in fights you were trying to avoid anyway. So before you commit to the Multi-Frequency jammer, the heaviest of the three at mass 7, pull up your ship stats and look at the numbers. If the hit to jump range or mobility looks rough, the lighter Dual-Frequency at mass 6, or even the Single-Frequency at mass 5, may serve you better while still keeping your contraband runs viable.
Where to Buy a Scan Jammer: Red Mile and Crimson Fleet
If you're ready to grab a Scan Jammer, there are really only two vendors worth tracking down — and the nice part is that both of them carry the same three models. The first is Lon Anderssen, who runs shop at the Red Mile on Porrima III, out in the Porrima system. You'll find him tucked behind the front desk; his workspace is labeled "Ship Services," so it's pretty hard to miss. Once you get him talking, pick the dialogue option "I'd like to view and modify my ships," and that'll open up the ship builder so you can browse his stock. One thing to keep in mind: like most ship technicians in the game, his inventory isn't guaranteed. Stock rotates, and some parts stay locked until you reach a certain player level. If the jammer you're after isn't showing up, it's worth circling back later or just trying the other vendor instead.
Your other option is Jasmine "Jazz" Durand, who runs a shop aboard the Key — the Crimson Fleet's main base. You'll find her in the space service room, which is where the Fleet handles all its ship business. There's one catch, though: she isn't there from the start. Jazz only begins selling her inventory after Naeva finishes her tour of the facility, so if she's nowhere to be found, go finish that intro sequence first and then circle back. Once she's set up, buying from her is about as painless as it gets. If you're already running with the Fleet and have access to the Key, she's honestly the easier of the two vendors to deal with, since you can pop in between missions instead of making a detour all the way out to Porrima III. Just don't count on a guaranteed stock list. Vendor inventory is partly random, so what's sitting on her shelf can be different every time you visit.
Vendor inventories in Starfield are partially randomized, which means you can walk up to the same ship services technician twice and see two totally different lineups. Nothing is guaranteed on a given visit, so an empty slot doesn't mean the part is gone for good — it just means it isn't there right now. It's also worth remembering that some modules are gated behind player level, so a low-level character may not even see certain items in a vendor's list, even from someone who normally stocks them. On top of that, not every ship technician in the settled systems carries these parts at all; the selection genuinely varies from one vendor to the next. So if Lon Anderssen at the Red Mile comes up empty, don't throw in the towel — head over to Jasmine Durand at the Key, and vice versa. If both of them are looking bare, try waiting or sleeping for a while in-game, since that refreshes a vendor's inventory and can cycle new stock into the list. Repeat visits don't cost you anything, so it's worth checking back rather than assuming the module doesn't exist in the game at all.
Scan Jammer Models, Stats, and Skill Requirements
There are three tiers of Scan Jammers, and picking between them really comes down to four things: how much evasion each one gives you, what it costs, how much mass it adds to your ship, and which rank of Starship Design you need before you can install it. The higher tiers give you better evasion, sure, but you'll pay for it — more credits, more mass, and a genuine skill investment if you're set on the top-end model.
| Model | Evasion | Skill Requirement | Cost | Mass |
|---|---|---|---|---|
| Single-Frequency | 10% | None | 2,700 credits | 5 |
| Dual-Frequency | 30% | Starship Design Rank 1 | 4,500 credits | 6 |
| Multi-Frequency | 50% | Starship Design Rank 2 | 9,000 credits | 7 |
INARA's database lists the Multi-Frequency module as a Class A part with mass 7, a value of 10,000 credits, a required level of 16, a manufacturer of Crimson Fleet, a 50% scan evasion bonus, and a Starship Design rank 2 requirement. Note the gap between the 9,000-credit purchase price players commonly report and the 10,000-credit listed value; vendor pricing and database values do not always match exactly.
If you are early in a playthrough and do not want to invest in Starship Design yet, the Single-Frequency model is a cheap entry point at 2,700 credits and no skill requirement. It only gives 10%, but 10% is better than nothing when you are hauling contraband through a UC checkpoint. Once you have the skill ranks, upgrade rather than adding a second unit.
Do Scan Jammers Stack? Understanding the 90% Cap
Scan Jammers do not stack. This is the single most misunderstood part of the system, and it is why so many players report that their jammers "do nothing." If you install more than one jammer, the game uses the lowest-rated one and ignores the rest. Extra units only add mass and waste credits.
The practical rule is simple: one jammer, and make it the best one you can afford and equip. Two Single-Frequency jammers do not equal 20%; they equal 10% plus dead weight. The same logic applies if you mix a Multi-Frequency and a Single-Frequency unit, the Single-Frequency value is what counts.
There is also a hard cap of 90% on contraband scan evasion. The Multi-Frequency jammer contributes 50%, and the Deception skill can make contraband scans up to 50% less effective, but the combined total cannot exceed 90%. That ceiling means you can never reach guaranteed passage, so always keep a contingency plan for a failed scan.
Why Your Scan Jammer Isn't Working: Common Mistakes
The most common cause of 0% evasion is contraband sitting on your character instead of in ship inventory. The jammer protects the ship, not your pockets. Before you jump, open your inventory and transfer every restricted item into the ship's cargo hold. This one mistake accounts for a huge share of the frustrated forum threads about jammers that appear broken.
The second most common cause is stacking. Players buy two or three jammers expecting the bonuses to add up, then wonder why their evasion never improves. Because only the lowest-rated unit counts, adding a cheap jammer next to a good one can actually downgrade your effective evasion. Sell the extras or leave them off the ship.
Forgetting the Equipment Plate is the third frequent issue, since the jammer will not mount on bare hull. Beyond that, remember that the jammer is only one layer of protection. Pair it with a Shielded Cargo Hold and invest in Deception if you plan to smuggle regularly, and accept that the 90% cap means risk never disappears entirely.
If you would rather not pay for a jammer at all, you can commandeer a ship that already has one installed. Crimson Fleet vessels are good targets because they frequently spawn with jamming modules. Starfield has no system for disassembling captured ships into parts, so you may need to fly the captured ship as your home ship to keep the module.
Shielded Cargo, Deception, and Building a Smuggling Loadout
A Scan Jammer is the centerpiece of a smuggling build, but it is not the whole build. The Shielded Cargo Hold hides a portion of your cargo from scans passively, and one shielded module is enough to cover the effect. Stacking shielded holds does not multiply the benefit the way new players often assume, so spend that mass budget elsewhere.
The Deception skill is the other major modifier. At higher ranks it can make contraband scans up to 50% less effective, which is a large swing on its own. Combined with a Multi-Frequency jammer, you are pushing toward the 90% cap, which is about as safe as contraband running gets in Starfield.
My usual loadout is a Multi-Frequency jammer on an Equipment Plate, a single Shielded Cargo Hold, and Deception ranked up as far as my character allows. That combination has carried me through dozens of UC and Freestar scans with only occasional incidents. The remaining risk is real, so keep your cargo compartment clean of anything you are not willing to lose, and never carry contraband on your person when you jump.
Frequently Asked Questions
How do I equip a Scan Jammer to my ship in Starfield?
Open the ship builder, place an Equipment Plate from the Structural tab, then go to the Equipment tab, select a Scan Jammer, and attach it on top of the Equipment Plate. You cannot mount it directly on the hull, so the plate is mandatory. Once attached, the evasion bonus applies automatically at contraband scans.
Where can I buy a Scan Jammer in Starfield?
Buy from Lon Anderssen at the Red Mile on Porrima III in the Porrima system, or from Jasmine "Jazz" Durand at the Crimson Fleet's base, the Key. Both stock the same three models. Vendor inventory is partially random and some items are level-gated, so check both locations if one comes up empty.
Do Scan Jammers stack in Starfield?
No. Scan Jammers do not stack. If you install more than one, only the lowest-rated jammer counts, and extra units just add mass and waste credits. Upgrade to a higher-tier model instead of adding duplicates. This is the most common reason players report that their jammers seem to do nothing.
What is the maximum contraband scan evasion in Starfield?
There is a hard cap of 90% for contraband scan evasion. The Multi-Frequency Scan Jammer gives 50%, and the Deception skill can reduce scan effectiveness by up to 50%, but the total cannot exceed 90%. That ceiling means a failed scan is always possible, so plan for the worst case.
