Experts in container rentals, sales & customization
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Frequently Asked Questions

shipping container FAQs

Why should I use containers instead of self storage units, like Public Storage?

Self storage facilities don’t offer as many benefits as storage containers. When you rent a shipping container, you have the flexibility to keep it at your location or ours, along with more sizes to choose from, higher security and more space for a lower price. With a self storage rental unit, you have less choice, space and security while costing considerably more. Shop and compare to see for yourself.

How do you compare to companies like PODS and CoolBox?

PODS and CoolBox don’t use ISO shipping containers; we do. 

The metal boxes non-ISO container companies use aren’t as strong and secure as our corrugated steel containers, which have one of the highest strength-to-weight ratios of any construction material. Additionally, they typically focus on residential moving and offsite storage, leading to higher prices and more inconvenience. 

What makes SMS different from other storage container providers?

We provide the best all-around value in steel containers. Unlike other ISO container companies, Southwest Mobile Storage provides you with one dedicated expert you can always rely on. Plus, no other conex box provider has our breadth and depth of container modification experience and capabilities. With vault-like security, superior service and unrivaled expertise and facilities, you’ll find that nobody else offers as much at our competitive prices.

Are shipping containers affected by condensation?

While the corrugated walls and roof of shipping containers helps prevent condensation, temperature variations will inevitably cause condensation on any metal surface.


Condensation is more likely to occur when the container has contact with cold, damp ground, so placing your container on dry ground or dunnage helps prevent it. You can also open the doors of your container to allow damp air to circulate out and to balance the internal and external temperatures of the container.

How do you open and close a shipping container?

To open a shipping container, ensure it’s completely unlocked. A standard container typically has two cargo doors on one end with two locking bars on each door. Starting on the righthand side, rotate the tabs on the locking bars and pull the bar handles away from the container and pull the door open. Repeat on the lefthand side. 


To close a shipping container, close the lefthand door. Place the bar handles back into their designated holders against the container and rotate the tabs to secure them. Repeat on the righthand side and lock your container. 

Can I order a container online?

We’re hoping to give you the ability to order shipping containers from us online soon. Until then, give us a call or start your container quote online and one of our container experts will contact you (usually within 1 business day) to finalize your order and arrange for delivery.

What if I need a size that's not standard?

Standard ISO containers are 8 feet wide by 8.5 feet tall and come in 20-foot or 40-foot lengths. We offer the widest variety of nonstandard container sizes for storage rental to meet your needs, including:

  • 10′ L x 8′ W x 8′ 6″ H
  • 15′ L x 8′ W x 8′ 6″ H
  • 24′ L x 8′ W x 8′ 6″ H
  • 30′ L x 8′ W x 8′ 6″ H
  • 45′ L x 8′ W x 8′ 6″ H

If you need something different, we can modify containers into any size you need, including double-wide, extra long or extra small.

What should I do in the event of a break-in or attempted break-in?

We provide you the most secure steel containers and ground-mounted mobile offices, but if someone attempts or successfully breaks into your unit, call the police to file a report. If the break-in damaged your rental container, call your dedicated container expert so we can assess and repair it.

How much notice do I need to give to access my container stored at your location?

Please notify your dedicated container expert at least one business day (24 hours) before you come to our yard so we can have your storage unit ready for your arrival. Access your shipping container stored at our location during business hours, which are Monday through Friday from 8 am to 5 pm local time. 

Do your shipping containers require any special care or maintenance?

Shipping containers require relatively little maintenance. We recommend spending a few minutes every few years oiling the door hinges and locking bars to ensure smooth opening and closing. Older containers may also need repainting or patches as dents or surface rust appear.


When you rent conex boxes from us, we recommend regularly inspecting your units for damage, defects and hazards so we can fix it for you as soon as possible. If you notice any problems, contact your dedicated container expert to notify us of any repairs needed to prevent safety hazards or damage to your contents and we’ll send one of our fabrication experts.

Why doesn't the US manufacture shipping containers?

Steel and labor are too expensive in the US to compete against Asian manufacturers, particularly China.

What are the ISO dimensions of your shipping containers?
Are shipping containers waterproof and air tight?

Because shipping containers are made for transporting cargo across the ocean on the decks of ships, they need to be wind and watertight (WWT) to avoid damaging the contents of the units. 


WWT containers are hole-less and have heavy duty rubber door seals to prevent water and other contaminants from entering any gaps between doors and walls. Used containers that aren’t WWT may have damaged door seals or holes, but we ensure any of these damages are repaired before delivery. 

What if you don't have a store in my area?

We’re able to deliver to remote areas that other companies won’t. We sell and modify shipping containers nationwide in addition to renting through all of Arizona, Colorado and Southern California. 

See our service areas for more information.

Where can I find information on storage container sizes?

Choose Rent, Buy or Modify under Commercial, Construction or Residential to see the sizes and layouts you can choose from. If you don’t see what you’re looking for, we can modify containers to any size you need! 

Do you require mandatory insurance or insurance certificates (COI)?

We require all rentals be insured and offer a Damage Liability Waiver (DLW) to insure your rental shipping containers, which costs 12% of the 28-day billing rate. The DLW covers damages (except graffiti) to your storage container and mobile office rentals but doesn’t cover loss or damage to your contents. The DLW is mandatory unless you provide your own insurance. 

Billing FAQs

How do I get a quote?

Fill out our quick Get a Quote form and one of our container experts will reach out to you to assess your needs, answer any questions you have and provide your quote. You can also start a chat with Sammie, our virtual container assistant, or call the branch closest to your delivery location

Do you accept cash payments?

We accept cash payments if you pay in person. 

Do I have to pay for my container up front?

With us, you don’t need to pay for your portable office or shipping container for sale until you’re ready to schedule delivery. At other companies, you’re required to pay all fees up front, regardless of if they have storage containers for sale in stock. 

Do you offer financing?

All sales must be paid for in full upon receiving your invoice, unless you’re purchasing a custom container. For custom containers, 50% is due before fabrication begins and the other 50% is due prior to shipment.

Can I get a record of my payments?

You can get a record of your payment history by calling our corporate office and asking to speak to our billing department. See our service areas for contact information. 

How can I make a payment?

Make a payment on our website with a credit or debit card using our SMS customer portal or giving us a call. You can also send your invoice and check in the mail to our corporate headquarters or pay cash in person. 

If I schedule pickup halfway through the month, will I only pay half the fee?

For the first 28-day billing cycle, we require a full payment. Once the minimum timeframe has been met, you can stop your rental part way through and we will prorate your rent by the day after pickup.

I should be on auto debit. Why am I getting an invoice?

We send all customers invoices regardless of being on auto debit. If you would like to stop receiving them, email

I requested pickup already. Why am I still being billed?

You’ll continue to be billed until we have picked up your storage container and our billing process has been finalized. A final, paid invoice may be sent out for your records.

Is there a fee if I pay by credit card?

We don’t charge credit card fees for rental payments except for a 3% convenience fee for purchases over $1,000.

When are my invoices due?

Invoices are due upon receipt unless otherwise specified on your invoice. Residential customers must enroll in auto debit.

What type of credit cards do you accept?

We accept all major credit cards including Visa, Mastercard, Discover and American Express.

Where do I mail my payments?

Please mail your payments to our corporate headquarters located at:

1005 N. 50th St.
Phoenix, AZ

Are you transparent with your rates?

We always disclose all fees up front and won’t charge you after your rental term unless we find major damage to your storage or office rental. In that case, we’ll be sure to discuss any damage and associated fees with you before billing you for it. 

What is the monthly fee for storage at your location?

Rental storage rates vary by the size of the container and branch. Contact us for a quote.

Do you prorate the rental payment?

All rentals are billed on a 28-day cycle. We prorate by the day starting one day after pickup of your rental storage container or mobile office.

container Delivery & Moving FAQs

Are there any items you can't transport in a container?

We won’t move units containing illegal substances, animals, humans, paint or flammables. 

Do I need planning permission to have a container on my property?

You typically do not need planning permission to keep a shipping container on your property. However, local laws and homeowners association restrictions vary widely, so consult your local regulations to be sure.

Do I need to be there to accept pickup of my loaded container?

You need to be there to unlock it so we can verify there are no prohibited items inside it and ensure everything is packed tightly enough to not slide during transit.

What if I can't be there for delivery?

You don’t have to be there for delivery as long as you’ve detailed where you would like your shipping container placed, cleared the area and ensured our drivers have access.

Do you level your containers when you deliver it?

We do a rough level of the container to ensure the doors will open and close correctly.

How do I arrange pickup?

Contact your dedicated container expert to arrange for one of our experienced drivers to pick it up.

What are the regulations for placing containers in a parking lot?

We can place your storage container or portable office in a parking lot as long as there’s enough clearance and our drivers can access it. You’ll need to check with the property manager for any restrictions on having storage or office containers in your lot.

What is the cost of delivery and pickup?

Delivery and pick up rates vary by region, distance and container size. Get a Quote for more information. 

What times do you deliver?

Our professional CDL drivers begin delivering as early as 6 am and continue until 2 pm Monday through Friday. If you need another time, we do our best to accommodate. We provide you a 2-hour delivery window, which is the most precise in the industry, and call 30 minutes before arrival.

What's the largest size I can move loaded?

Due to the combined weight of the container, its contents and the trailer hauling it, Department of Transportation and industry-wide standards limit us to moving loaded 20-foot shipping containers or smaller only. 

Will a container fit into a parking space?

Parking spaces in the United States are typically 19 feet deep by 8.5 or 9 feet wide, so any standard width containers smaller than 19 feet long will fit into a parking space. 15-foot containers are the largest size we offer that fits in a parking space.

Will it damage my driveway?

As long as you’ve provided the necessary clearance space, there should be no damage during your container delivery and pickup. Our steel containers are delivered with precision by highly experienced drivers and placed onto wood dunnage blocks to prevent damage to your surface. 

Will you move a loaded 40ft container?

The Department of Transportation has weight restrictions and safety precautions that do not allow us to pick up or transport loaded 40-foot shipping containers. We can only move 20-foot shipping containers or smaller, according to industry standards.

What if I don't have room at my location for a shipping container to be delivered?

We can keep your storage container as long as you need at one of our secure container yards in Arizona, California or Colorado. Give the branch nearest you at least one business day (24 hours) notice before you visit to access your container. We’re always happy to deliver it to you when you have the space for it later.

Container Rental FAQs

Do you have climate control storage containers?

We offer rental containers that are temperature controlled, which are units that offer thermostat control up to 10 degrees of the outside temperature using heating, ventilation and air conditioning (HVAC) that you just have to plug into a power source or extension cord. All our mobile offices for rent come with insulation and HVAC installed. 


We designed these insulated containers with HVAC with restoration companies in mind because we know your clients need extra protection for their items.

Do you offer modular offices?

All our portable offices are ground-mounted. Modular offices are built onto a foundation that keeps your office above ground level. They often require assembly and installation once delivered to your desired location. Our mobile offices rest on the ground and do not need to be assembled or installed on delivery. Simply hook it up to a generator or other power source instead.

Can I rent more than one shipping container from you?

You sure can. Contact the branch nearest your shipping container delivery location to speak to one of our experts about renting multiple conexes.

Can I alter the rental container or add to it myself?

You can alter our rental containers and portable offices. Any alterations must be undone and the unit must be in original condition upon return. You can also choose add-ons, accessories and utilities for your rental storage and office containers from our list of rental options.

Do you have containers with side access doors to rent?

We have a limited amount of containers with roll up doors for side access available to rent. Speak to your dedicated container expert for more information. 

Do you rent containers nationwide?

We offer the ability to purchase or modify shipping containers nationwide. You can rent, buy or modify ISO containers at our branches in Arizona, California and Colorado. 

How long can I keep my storage container at my location?

Keep your rental storage container at your location for as long as you need. Once you’re finished using the container, let your dedicated container expert know and we will pick it up for you.

Do you have wet offices with plumbing to rent?

We don’t rent out mobile offices with plumbing, but we can modify portable offices and storage containers to have it for you.

Do you offer spray foam insulation in any of the units?

We can add spray foam insulation to 20-foot and 40-foot storage containers for rent. All of our mobile offices come with insulation and HVAC already installed.

How much are rental rates for a 20ft container?

The cost to rent 20-foot storage and office containers depends on many factors, like your location, current inventory, market prices and any rental options you add. Plus, the type of rental unit, such as storage or workspace, will influence your rate.


Get a Quote or contact the branch closest to your delivery location for 20-foot container rental prices.

How much does it cost to rent a 40ft container?

Rental rates for 40-foot storage and office containers depends on your location, our current availability, market rates and the rental options you choose to add. It also depends on the type of rental unit you need, such as whether you are renting a storage container or one of our mobile offices.


Get a Quote or contact the branch closest to your delivery location for 40-foot container rental prices.

Is there a minimum amount of time I can rent a container for?

We require a minimum one month rental period. If you only need your container for a few days or weeks past the first 28-day billing cycle, we’ll prorate your rent.

Do you rent containers long-term?

We sure do. You can rent our shipping containers as long as you need.

What size containers do you rent?

We have shipping containers for rent in a variety of sizes starting at 10 feet up to 45 feet long and portable offices from 10 feet to 40 feet long. We can also modify containers to fit whatever size you need.

containers for sale FAQs

Can you relocate units for me after I buy a container from you?

We can pick up and relocate any storage containers and mobile offices you or your business owns if you need to move them at a later date. Contact us for a quote.

Do you buy back containers?

We generally buy back used shipping containers depending on unit condition, our inventory and the current market.

Do you offer a guarantee on your shipping containers for sale?

When you buy a shipping container from us, we offer a six month warranty on new one-trip and refurbished containers and a one year warranty on modified containers.

Am I able to view storage containers before I buy?

Check out our ISO containers for sale at any of our container show yards in Phoenix, Tucson, San Diego, Los Angeles and Denver areas. You’ll get to see different types of shipping containers for sale we offer, helping you choose the right container for your needs.

How much is a new one-trip container?

The price of a new container depends on many factors, like your location, our current availability, market rates and the buy options you choose to add. Plus, whether you want to modify it or not. One-trip containers are the best value as they only made one cargo trip so they’re the newest possible option to buy.


Get a Quote or contact the branch closest to your delivery location for new one-trip container prices.

How much does a used container cost?

Used container prices depend on your location, available inventory, global and regional market rates and any buy options you add. Plus, the condition of the container and whether you want to modify it or not. We offer wind and watertight (WWT) and refurbished containers for sale. WWT containers are a good value as they’re weather-resistant and typically under 10 years old. Refurbished containers are a better value. They’re WWT, spot-grinded, primed and repainted.


Get a Quote or contact the branch closest to your delivery location for used shipping container prices.

custom container FAQs

Do I need a design or drawing for my modified container?

You will need to provide a basic design, so we have an idea of what you want. We can draft the rest of your design based on any changes you request; however, we don’t correspond with zoning and/or permitting departments. 

Do you require a deposit for custom containers?

We ask that you pay 50% of the total cost of your container modification before we start construction on it. The final 50% is due before we ship it to you.

I have a large project in the pipeline. Would you be able to handle it?

Our 90,000 sq ft fabrication facility has an extensive staff of certified welders, electricians, plumbers, carpenters, engineers, painters and fabricators that frequently handle multiple container modification projects at a time. With such a large in-house staff and indoor facility, we’re able to provide you with precise, consistently high quality custom shipping containers no matter the size of your project. 

Do you offer a guarantee for modified shipping containers?

Modified containers come with an industry standard one year warranty.

Do you buy back containers that have been modified?

We may buy back a custom container, depending on the type of modifications, the condition of the container, our current inventory and market conditions. 

Do you have engineers on staff that can provide drawings?

We have engineers on staff who can provide basic drawings in the process of building your custom container; however, we don’t provide engineered or CAD drawings. 

What types of containers do you use for your construction?

We use ISO standard containers in varying condition for modifications. Choose from wind and weathertight (WWT) or one-trip containers, based on your needs and budget. 

What size containers do you modify?

We can custom build anything and modify containers to any size that you need. Whether you need an extra wide container or a multistory structure, the possibilities are endless.