Britax Allegiance 3-Stage Convertible Car Seat Review

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In today’s Britax Allegiance Review, we aim to give you an unbiased in-depth analysis of the product so you can decide whether this is for you.  

Making a decision about which car seat to purchase for your child can be difficult. Aside from safety and ease of use, you should also consider comfortability and whether the seat is appropriate for your vehicle.  

We hope to help your decision process because that can be exhaustive for you as a parent. Today, we’ll be examining one of the top car seats in the market, the Britax Allegiance convertible car seat, in an attempt to save time and effort.

Overall, the Britax Allegiance is one of the most affordable convertible car seats, and it ensures your child’s safety and comfort.

The Britax Allegiance is one of the best infant car seats along with the Uppababy MESA and Chicco KeyFit 30 in our recommended Narrow Car Seats.

Amazon has seasonal offers from time to time. Check it out to know if there is an ongoing offer.

Is affordability the only perk about this car seat? Let’s read on to find out. 

Britax Allegiance Review : Image: Amazon
Image: Amazon

Table of Contents

Pros & Cons of the Britax Allegiance Convertible Car Seat


  • Easy installation.
  • 2 installation modes(Rear-facing and Forward-facing).
  • Easy adjustability and connection with a latch that can be connected to push-button latch connectors.
  • No-rethread harness system.
  • Seat Belt lock-off option.
  • Safe (FAA-approved; No chemically-treated materials)


  • Seat Belt lock-offs seem like cheaper plastic.
  • SIngle layer padding.
  • Headrest is not adjustable.
  • Does not come with a cup holder.

What is the Britax Allegiance Convertible Car Seat?

Britax Allegiance Review: Image: Official website
Image: Official website

Britax allegiance is one of the Britax convertible car seats that can be easily switched from rear-facing to forward-facing as your baby grows. 

Designed with Britax safety technologies, this car seat features quick-push latch connectors, the patented Britax SafeCell Impact Protection for protection during crashes, and protective shell foam that surrounds the head, neck, and torso region. 

The Essentials by Britax convertible car seat series has two different models, the Britax Allegiance and Britax Emblem. They both have similar features and installation methods but the Britax Emblem is more padded for greater comfort and safety. 

Tip: Contrary to infant car seats, convertible car seats can be installed rear-facing, then turned around to face the front after a certain age. Each state has its own laws regarding when a seat can be turned around, as well as restrictions on height, age, and weight.
For the rear-facing mode, your baby will be rear-facing and on the back seat, you might consider placing a little car seat mirror to keep an eye on your child while driving.

What comes with the Britax Allegiance  Convertible Car Seat?

The Britax Allegiance comes with a removable body pillow to ensure newborns fit well, a Latch with push-button latch anchors, an easy-to-remove seat cover, an adjustable headrest, a rear-facing mode, and a forward-facing mode. 

Unlike the Diono Radian 3RXT , this car seat does not come with a cup holder; most parents ordered the Britax child cup holder for convertible seats together with the seat.

Allegiance is one of the few convertible seats that are easy to maintain since the cover can be removed for cleaning; however, a machine-washable fabric cover would have made it the best in terms of maintenance.

Who is Britax Allegiance for?

If you are looking for a safe, easy-to-use and inexpensive car seat for your child, this car seat is for you. In comparison to other brands of convertible car seats, the Britax Allegiance is less expensive while still providing the same level of safety and quality.

The no-rethread harness system makes it easier to adjust the height of the harness straps in 10 positions to be able to fit across your child’s shoulder. This Britax Allgiance car seat is only 18.5 inches wide which makes it narrow enough to fit perfectly into most mid-sized vehicles and may even fit in a 3-across position for some specific vehicle models. 

The rear-facing mode is designed for babies weighing 5 – 40 pounds while the forward-facing mode is for children between 20 – 60 pounds in weight. 

If you are seeking a convertible car seat that isn’t so heavy to carry, the Britax Allegiance may be the right choice for you. At only 19.5 pounds, it remains relatively light in comparison to other car seat models.

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Where to buy a Britax Allegiance Car Seat?

In general, Amazon will be a fast and easy option.

Overall Rating

  • Overall: ⭐⭐⭐⭐⭐(4.6 out of 5)
  • Safety: ⭐⭐⭐⭐⭐ (4.7 out of 5)
  • Durability: ⭐⭐⭐⭐ (4.4 out of 5)
  • Ease of Use: ⭐⭐⭐⭐⭐ (4.5 out of 5)
  • Market Reviews: ⭐⭐⭐⭐⭐ (4.8 out of 5)
Our evaluation of this product is based on 4 metrics: 1) Safety, 2) Durability and 3) Ease of use, and 4) Market Consensus. We write about each of these metrics in its own section below. 

#1. Safety – How Safe is Britax Allegiance Convertible Car Seat? 

Britax Allegiance Review: Image: Amazon
Image: Amazon

Total Safety Score = ⭐⭐⭐⭐⭐ (4.5 out of 5)

In terms of Safety, we rate the  Britax Allegiance car seat based on the formula below: 

Safety Score = Safety Features + Certifications + Recall/Quality Issues 

Safety Features ⭐⭐⭐⭐

This car seat has amazing safety features, but we have seen more advanced safety features, hence the 4-star.

  • Britax SafeCell Impact Protection system
    • Side impact protection
    • Impact stabilizing steel frame
    • Impact-absorbing base, 
    • V-shaped tether 
  • Push-button latch connectors with built-in lock-offs for firm connection. 
  • No-rethread harness system.

In most cases, parents felt their babies were comfortable and safe in this seat. The seat is sturdy and the one layer of padding is comfortable enough to sink your child in a good state of rest. But the Britax Emblem would be a better choice if you are looking for a more padded car seat. 

Connecting the latch to the latch connectors seems fancy and secure. However, if your child is tall enough, he/she may reach the connectors and push the button to loosen the strap, rendering the seat unsafe.

This is why we recommend that you place a car seat mirror to keep an eye on your child while driving.

A crash test result earned the Allegiance a respectable score for crash tests and the best Head Injury Criterion (HIC) results. 

Safety Certifications ⭐⭐⭐⭐⭐

Car: This child seat system conforms to all applicable Federal Motor Vehicle Safety Standards (FMVSS 213). 

Flight: This child seat is certified for aircraft use. Most airlines in the U.S. and Canada will allow the use of a child seat as long as it is labeled as an approved child seat for use in aircraft and fits properly on the aircraft seat. Contact the airline about their policy prior to traveling.

Note: The FAA recommends that a child weighing up to 40 lbs (18 kg) use a certified, harnessed child seat while traveling on an aircraft.

Recall/Quality Issues ⭐⭐⭐⭐

At this time, there are no known recalls for Britax Allegiance Convertible Car seats.

The only complaint on the NHTSA’s database, at the time of writing this review, was from a parent who was driving at 70mph on the highway when she noticed her child’s arms were completely out of the straps after pressing the push button to release the straps.

We also spotted rare reports about the bad and dirty smell of the products; this may be due to storage or delivery process issues.

Tips: Keep your receipt. You should examine all sections of the seat as soon as you receive it. The sooner you can reach out to customer support, the better, as they might be slow to respond at times. Be ready to take pictures of the product defects if any. 

#2. Durability: How Long Can You Use Britax Allegiance Convertible Car Seat?

Britax Allegiance Review : Image: Amazon
Image: Amazon

Total Durability Score = ⭐⭐⭐⭐(4.4 out of 5)

In terms of Ease of Use, we rate the Britax Allegiance based on the formula below: 

Durability Score = Range of Use + Expiration + Warranty

Range of Use ⭐⭐⭐⭐

  • Minimum weight limit recommendation is ‎5 pounds (2.3kg) which should be equivalent to a 2-month old baby.
  • The maximum weight limit recommendation is 65 pounds (29.5kg) suitable for children between 5 and 7 years of age. Pretty good range.
  • Child Standing Height should be 49″(124.46 cm) or less for both rear and forward-facing modes. 
  • Child Seated Shoulder Height should be 9 – 16.75” (22.86-42.54 cm) for rear-facing and forward-facing modes.
  • Rear-facing weight range is 5 pounds (2.3kg) – 40 pounds (18.1kg)
  • Forward-facing weight range is 20 pounds (9.1kg) – 65 pounds (29.5kg)
  • Weight range: ‎5 Pounds (2.3kg) – ‎65 Pounds (29.5kg)
For the best use of the car seat, the manufacturer recommends the Range of Use. Exceeding those limits might be okay if you had to. In the end, though, it is about risk, safety, and your child’s comfort.If your baby weighs less than the minimum weight and height limit, you should not put them in the car seat. Additionally, the maximum weight and height limit also tells you if your child has outgrown the car seat, if you can’t already tell or if they aren’t complaining about it.

Expiration ⭐⭐⭐⭐

The Britax Allegiance car seat expires 7 years from the manufacture date. We have seen 10-years in the market. Hence the deduction of 1 star.

Most car seats have their product life due to the constant wear and tear and hot/cold temperature change with different places you go.

Keep an eye on the expiration date as a safety precaution for your youngster. This information is provided by baby car seat manufacturers depending on the design and materials they employ. Due to the typical predicted wear and tear, car seats that have beyond their expiration dates are more likely to have safety hazards.

Warranty ⭐⭐⭐⭐⭐

1-year warranty from the date of original retail purchase.

#3. Ease of Use: How Will Britax Allegiance Convertible Car Seat Fit into Your car?

Britax Allegiance Review: Image: Amazon
Image: Amazon

Total Ease of Use Score: ⭐⭐⭐⭐⭐(4.5 out of 5)

In short, everything is okay. The car seat is not so heavy compared to other car seat brands. 

In terms of Ease of Use, we rate the Britax Allegiance car set based on the formula below: 

Ease of use = 

Installation + Adjustability + Maintenance + Carry +Stroller Compatibility

Installation ⭐⭐⭐⭐

NHTSA has not endorsed this car seat for installation, so our review is based on research and from the installation manual. 

Some users had difficulties in installing this car seat. But if you read the manual of the car seat and the section in your vehicle manual about child safety seats before installation, then it may be fairly simple.  

The car seat accessories are arranged in the storage slots in the base of the seat. 

Rear-facing Installation

Note: This child seat must be reclined to position 3 when installing rear facing.

  • Place the seat rear-facing and in a flat position on the  vehicle seat, lift the harness adjuster lever and pull both harness straps forward to unbuckle the harness. Next is to remove the body pillow and belly pad. 
  • Pull the seat portion of the cover forward to access the belt pack ensuring that the buckle is pulled through the cover. 
  • Route the vehicle seat belt through the rear-facing belt slots and buckle while ensuring that the belt is not twisted.
  • Use one and push the child seat into the vehicle seat and use the other to remove any slack. 
  • Check to make sure the installation is secure as the child seat should not move more than an inch sideways or front to back.

Here is a video on how to install a Britax Allegiance Rear-facing 

Latch rear-facing Installation  

  • Installing with the latch requires that you first remove the lower connectors from the storage slots; press and hold the adjust release button for both straps to pull the straps to full length.
  • Incline the seat and place it on the vehicle seat. Press the lower connectors firmly onto the adjacent lower anchors. Push the car seat down while pulling the latch straps tight ensuring that the straps are not twisted.
  • Check to make sure the installation is secure as the child seat should not move more than an inch sideways or front to back.

Forward-facing Installation

Note: This child seat must be reclined to position 1 or 2 when installing forward facing.

  • Get the lower connectors from the storage slots in the base and pull the both lower connector straps to full length while pressing the adjuster buttons.
  • Remove the tether from the pouch and place it up and over the back.
  • Firmly press the lower connectors onto the adjacent lower anchors until it clicks while ensuring that the strap is not twisted. 
  • Push the car seat down while pulling the lower connector straps to tighten.
  • Attach the tether to a designated anchor (see vehicle owner’s manual) and remove the slack.
  • Wrap excess webbing in the elastic strap and store in the tether storage pouch.

Here is a video on how to install a Britax Allegiance Forward-facing 

Adjustability ⭐⭐⭐⭐⭐

The no-rethread height adjustment system for the harness straps and height of the headrest is an intriguing feature of the car seat. Users do not need to engage the process of buckling and unbuckling to adjust the harness and height. 

The 10-Position Harness & Headrest easily adjusts to grow with your baby while the 3-Position Recline helps you find the most comfortable fit for your child and the best fit for your vehicle.

This car seat is comfortable and the adjustability features make it great for use even as your child grows older.


The seat cover can easily be removed during maintenance. However, some users reported that after constant removal, it becomes loose and does not tighten.

Also, there may be wear and tear of the cover if overly maintained, a solution would be to get a waterproof seat protector over the fabric. 

Carry-Around ⭐⭐⭐⭐

Britax Allegiance Review : Image: Amazon
Image: Amazon

With a carrier weight of 19.5lbs, this seat is not heavy as compared to other brands of convertible car seat. It can be lifted in and out of the car.

Stroller Compatibility ⭐⭐⭐

Britax Allegiance is not stroller compatible. Only meant to be used as a car seat. 

Measures & Specs

  • Seat Weight: 19.5 lbs / 8.85 kg
  • Product Height: 29.5 in / 74.93 cm
  • Product Width: 18.25 in / 46.35 cm
  • Sitting Area Depth: 11 in / 27.94 cm
  • Maximum User Height: 49 in /124.46 cm
  • Number of Head Support Positions: 10
  • Material Type: Alloy Steel.
  • Harness type: ‎5-Point.
  • Item Weight: ‎19.5 pounds.
  • LATCH connectors with push-button that makes installation easy.

#4. Market Consensus: What others say about Britax Allegiance

Total Market Consensus ⭐⭐⭐⭐⭐ (4.8 out of 5)

In terms of Market Consensus, we rate the Britax Allegiance with a 5 star based on the formula below:

Market Consensus =
Customer Feedback (Quantitative) + Expert Reviews (Qualitative)

Customer Reviews ⭐⭐⭐⭐⭐

Overall Rating (4.8 out of 5 based on 1,063 ratings)

Note that for highly-rated products, we will avoid bombarding you with more praises about the product. We intentionally look for substantiated negative reviews or criticisms that add to our knowledge. 

So, if you’re going to jump right into this section, know it has its own merits we’ve discussed before. 

Selected Critical Britax Allegiance Review

⭐⭐I really wanted to like this car seat but I just didn’t. First off, the covers don’t come off to wash? For a kids seat? Secondly adjusting the seat (buckle, headrest, recline) is tough and kind of sticks. I need a seat that I can operate if my child is fussing or when I might only have one hand free. This seat gave me a lot of trouble. Also, when it comes to the price point for the seat, I expected an anchor latch so that I wouldn’t need to yank the strap to tighten it in the car. Once again, this seat just didn’t check the boxes that I need for a functional car seat. – Amazon review

⭐⭐⭐I’ve had Britax car seats before, and this one is extremely heavy and large. It almost didn’t fit in my babysitter’s car. Features are not intuitive and I had to look up everything in the manual including adjusting straps. There is no button on your outside to adjust the straps. Even though I know where the bottom is inside, it’s still difficult to locate, and that’s the last thing anyone needs with a screaming toddler. I will be looking for a car seat that’s lighter with a button to adjust the straps. – Amazon Review

⭐⭐⭐⭐⭐I absolutely love this car seat. I’ve owned and installed 6 different brands and models of car seats, and this is the easiest one to install. I even prefer it over the Britax Clicktight, which I was surprised about. This car seat is very sturdy, and is compact enough to fit rear-facing and reclined in my little Mazda 3, which I’ve struggled to do with other car seats. – Amazon Review

Expert Reviews (Insufficient data)

“Britax produces the best convertible car seat product.” –

“After 20 hours of research, including testing nine popular convertible car seats at home and crash-testing six finalists in a top lab to measure their side-impact performance, we think the Britax Marathon ClickTight is the best one for most families.” – Wirecutter 

Britax Allegiance VS Britax Marathon ClickTight 

As mentioned, Wirecutter considers the Britax Marathon Clicktight to be the best convertible car seat. 

For us, we like the Britax Allegiance because it’s cheaper, can be forward- and rear-facing, and is a lot lighter.

Below are key differences between Britax Allegiance and Britax Marathon ClickTight.

Britax Marathon ClickTight Britax Allegiance 
InstallationEasy to install Not as easy to install
PriceMore expensiveLess expensive
OrientationRear-facingRear and forward-facing
Installation typeSeat beltLatch
MaterialSteel and mesh fabricAlloy steel
Number of reclining positions143
Weight27 pounds19.5 pounds

Conclusion of Britax Allegiance Review

We would recommend the Britax Allegiance as a brand for your car seat needs. 

It is a perfect choice for parents who are on a tight budget and still want their child to be safe and secure while driving. With Britax Allegiance, children are safe and comfortable. The seat can be adjusted so your child can grow with it.  

Head on to amazon to check if there is a deal and grab it now if you are interested.

Frequently Asked Questions (FAQs)

Q1. What are the other Britax Allegiance models out there? 

The 2 models of the Britax Allegiance car seat are Luna and Prism. The difference is just in the color and each model also has different color types. 

Q2. Is there any difference between Britax Allegiance and Britax Allegiance 3 Stage? 

No difference.

Q3. How long is Britax Allegiance good for?

The car seat can be used for a duration of 7 years after the manufacturing date.

Q4. What does Britax Allegiance weigh?

The Britax Allegiance is 19.5 pounds in weight.

Q5. What is the difference between Britax Allegiance and Emblem?

Britax Emblem has 2 layers of side impact protection while the Allegiance has only 1 layer. Both models are the only car seats in the Essentials by Britax Convertible car seat series. 

Q5. How wide is the Britax Allegiance?

The Allegiance is 18.25 in / 46.35 cm in width, narrow enough to fit 3-across in most mid-sized vehicles. 

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Shane is passionate about researching baby stuff for his baby girl. He worked for a premium brand consultancy. He runs the research on this site.