How To Fix Southwest Error Code 503999999 And Access Your Account [Guide]


The Southwest error code 503999999 is a frustrating issue that prevents customers from accessing their Southwest account online or via the mobile app. This error essentially means that something unexpected occurred on Southwest’s end which blocked access to your account.

While the root cause of error code 503999999 can vary, the good news is that there are several troubleshooting steps you can try on your end to potentially resolve it. Clearing your browser cache, trying different devices, updating your apps, and contacting Southwest support are some of the methods that often work to fix southwest  error code 503999999.

Recent Released: Is a Safe and Legal Option for Streaming Movies and TV Shows? An In-Depth Review

This guide will provide an overview of the common causes of error code 503999999, along with actionable troubleshooting solutions you can implement right away. We’ll also cover tips for accessing your Southwest account if the website itself seems to be down. Follow the steps below to get your account up and running again.

Common Causes of Error Code 503999999

Before we get into the specific fixes, it’s helpful to understand what typically triggers the 503999999 error on Southwest’s website and mobile platforms.

Some of the most common reasons include:

  • Temporary browser issues: Outdated caches, cookies, or browsing data on your specific device can sometimes interfere with accessing Clearing your browser data is one of the first things to try when error 503999999 appears.
  • Problems with your internet connection: If you have an unstable/slow internet connection, it can potentially disrupt communications between your device and Southwest’s servers. Make sure you have a strong Wi-Fi or cellular data connection when attempting to access your account.
  • Incompatible apps or operating systems: The Southwest mobile app or website may fail to load properly if you have outdated app versions or an older OS. Keeping your apps, operating systems, and devices updated is key.
  • Website downtime: occasionally undergoes scheduled maintenance or experiences unplanned outages. This can prevent account access across any device.
  • Temporary issue on Southwest’s servers: Sometimes a server hiccup on Southwest’s end can lead to a 503999999 error, even if your device and internet connection are fine.

The solutions outlined in the next sections aim to address each of these potential causes, resolving the error for good.

Clear Browser Cache and Cookies

One of the first troubleshooting steps to attempt when you see error code 503999999 is to clear your browser’s cache and cookies for

Over time, your browser will accumulate temporary internet files, browsing histories, cached data from sites you visited, and more. Excessive cached data can sometimes disrupt communications between your browser and site servers.

Clearing this data gives your browser a fresh start, removing any corrupt files or outdated cookie values that could be interfering with accessing your Southwest account.

Follow these instructions to clear your cache and cookies:

Google Chrome

  1. Open Chrome browser and click the 3 vertical dots in the top right to open the menu
  2. Select Settings from the menu
  3. Click Privacy and Security in the left sidebar
  4. Select Clear browsing data
  5. Choose a time range from the top drop-down menu, or select All time to clear everything
  6. Check the boxes for Cookies, Cache, and Cached images/files
  7. Click Clear data


  1. Open Safari and click Safari in the top left corner
  2. Select Preferences from the dropdown menu
  3. Go to the Privacy tab
  4. Click Manage Website Data
  5. Select from the list
  6. Click Remove


  1. Click the 3 lines in the top right, go to Options
  2. Select Privacy & Security in the left sidebar
  3. Under Cookies and Site Data, click Clear Data
  4. Select the box for Cookies and Site Data
  5. Click Clear

Microsoft Edge

  1. Open Edge and click the 3 dots in the top right
  2. Hover over Settings and select Clear browsing data
  3. Choose a time range, or select All time
  4. Check the boxes for Cookies, Cached images and files
  5. Click Clear now

Once the process completes, try reloading to access your account again. This often resolves error 503999999 by clearing away any problematic cached files.

Check Your Internet Connection

Another simple thing to check is that your internet connection is stable and strong whenever you attempt to access your Southwest account online or via mobile.

Weak Wi-Fi signals, cellular data issues, network outages, or general connectivity problems can disrupt communications between your device and Southwest’s servers. This can sometimes manifest as a 503999999 error when trying to load your account.

Follow these tips for trouble-free internet access:

  • Restart your Wi-Fi router and modem – Power cycle your network devices to refresh the connections.
  • Switch from Wi-Fi to cellular data – Or vice versa. Try accessing your account using a different network.
  • Run an internet speed test – Use a tool like to check your current download/upload speeds.
  • Move closer to your router – If on Wi-Fi, get nearer to the router for strongest signal.
  • Reset network settings – On mobile, reset network settings under Settings to refresh connections.
  • Contact your ISP – If network issues persist, call your ISP to troubleshoot or report an outage.

Once you’ve confirmed your internet access is strong, try loading your Southwest account again while connected. With network issues ruled out, you can move on to other fixes if error 503999999 still appears.

Try a Different Browser or Device

If clearing caches and checking your internet didn’t resolve the 503999999 error, the next step is to try a different web browser or device altogether.

This method essentially helps you isolate whether the problem is specifically with your current browser, or something more general on Southwest’s end.

For example, Chrome users who receive the error code can attempt loading in Firefox or Safari instead. Similarly, you can switch between your computer, smartphone, or tablet to access your account.

Here are some variations to try:

Different browsers:

  • Chrome –> Firefox
  • Safari –> Chrome
  • Firefox –> Edge

Different devices:

  • Phone –> Computer
  • Tablet –> Laptop
  • Desktop –> Mobile

The key is testing whether loads properly in a completely different browser on another device. If you are able to access your account normally from an alternate browser or device, the 503999999 error is likely isolated to your original access point. This indicates an underlying issue with that particular browser/device rather than Southwest’s website.

Some further steps in this case include:

  • Updating your problem browser or resetting browser settings
  • Updating software/OS on a problem mobile device
  • Trying advanced cache/data clearing on the problem browser/device

Conversely, if error 503999999 persists across every browser and device you try, the issue is likely on Southwest’s end. Contacting customer support, trying again later, or using a VPN would be the next logical troubleshooting steps.

Update Your Southwest App and Operating System

If you are encountering error 503999999 when using the Southwest mobile app specifically, an app or device software update may be required.

The Southwest app occasionally releases new versions containing bug fixes, performance patches, and compatibility improvements. Using an outdated version can create problems accessing your account.

Likewise, your device’s iOS or Android operating system also periodically receives major updates from Apple or Google. Running an old OS can similarly disrupt usage of the Southwest app.

Follow these best practices:

For the Southwest app:

  • Open your device’s App Store/Google Play Store app
  • Search for Southwest Airlines
  • If an Update option shows, tap it to upgrade to latest version
  • Alternatively, uninstall and reinstall the app

For your device OS:

  • On an iPhone, go to Settings > General > Software Update to install iOS updates
  • On Android, go to Settings > System > System updates to get Android updates
  • Or, check for a software update prompt during initial device setup after a factory reset

Keep your Southwest app and device OS fully up to date whenever new versions are released to enjoy the most seamless, glitch-free experience. This prevents most app-specific errors like 503999999.

Contact Southwest Airlines Customer Support

If you have tried all the troubleshooting steps above and are still seeing error code 503999999, your next best option is to contact Southwest Airlines customer support for assistance.

The Southwest support team may be able to resolve the error on their end or provide tailored troubleshooting guidance based on your account specifics.

You can reach out to Southwest customer support by:

Some key details to provide the support reps include:

  • Your Southwest Rapid Rewards number or confirmation code/number
  • What device(s) and browser(s) you are using
  • Whether the error occurs on mobile, desktop, or both
  • Any troubleshooting you’ve already attempted
  • Error code number shown (503999999)
  • Screenshots of the error if possible

Southwest’s customer service team can use this info to investigate the underlying cause and resolve error code 503999999 for your account more efficiently. Be sure to also ask if there are any identified website issues on their end.

Access Account via VPN or During Non-Peak Times

If itself seems to be experiencing downtime or you are receiving general “website unavailable” errors, using a VPN or trying during non-peak times/days may allow you to access your account.

Try a VPN service

A VPN (Virtual Private Network) lets you bypass network restrictions by routing your traffic through remote servers. This essentially gives you an alternate “location” to connect from.

Reputable VPN providers include NordVPN, ExpressVPN, CyberGhost, Private Internet Access, and TunnelBear.

To use a VPN:

  1. Sign up for a paid VPN service
  2. Download & install the VPN provider’s app on your device
  3. Connect to a US-based VPN server to mask your location
  4. Launch in your browser
  5. Sign in and access your account as normal

The VPN network can help you get around any temporary blocks or issues on Southwest’s end.

Attempt access during off-peak hours tends to experience the highest traffic during the mornings and evenings on weekdays. Attempting to access your account during less busy periods can boost reliability.

Try checking your account status:

  • Late at night or early mornings
  • Weekend days (Saturday/Sunday)
  • Mid-afternoon windows on weekdays

Avoiding peak congestion times lessens the chance of errors and gives Southwest’s servers more available bandwidth for your requests. With fewer users competing for resources, you’re more likely able to sign in uninterrupted.

Conclusion & Next Steps

Error 503999999 can prevent you from accessing your Southwest Airlines account, making it difficult to check reservations or make changes. But as outlined in this guide, the solutions above can typically resolve such access issues relatively quickly.

Clearing your browser data, checking internet connectivity, switching devices, updating software, contacting support, and using a VPN during website downtime are all proven methods for overcoming Southwest error code 503999999 or general account access problems.

To recap the key troubleshooting takeaways:

  • Clear browser caches/cookies to remove corrupt files interfering with account access
  • Ensure your internet connection is stable whenever trying to access your account
  • Try alternate browsers and devices to isolate the source of the problem
  • Keep Southwest apps & device operating systems updated
  • Contact Southwest support for individualized troubleshooting help
  • Consider a VPN service or attempt access during off-peak hours if seems entirely unavailable

With consistent testing and patience, one of these solutions should successfully get rid of error 503999999, allowing you to sign in to your Southwest account as expected once again.

Frequently Asked Questions

What causes error code 503999999 on Southwest?

Some common causes are browser cache issues, software incompatibilities, website downtime, server problems, and general network connectivity disruptions. The specific root cause can vary in each case.

Does Southwest error code 503999999 mean my account was hacked?

No, this error is not related to hacking or account security breaches. It simply indicates a temporary technical issue is preventing access to your account from your device. Your account and info are still safe.

Why does my Southwest app keep showing error 503999999?

For mobile app issues, the cause is usually an outdated version of the app itself or your device’s operating system being too old. Update both to the latest versions. Reinstalling the app can also help.

I keep getting Southwest error 503999999 on my laptop – what should I do?

On desktop platforms, clearing your browser caches, trying a different browser, checking your internet connection, and rebooting your modem/router are good starting points for troubleshooting.

What’s the best way to contact Southwest Airlines about error 503999999?

You can call 1-800-435-9792, message them on Twitter @SouthwestAir, email, or submit a contact form on their website. Provide your account details and describe the error.


Error 503999999 can certainly be frustrating, but carefully working through fixes like clearing your browser, updating software, trying different devices, and contacting customer support will help you regain access to your Southwest Airlines account. The tips in this guide aim to get you up and running again quickly so you can manage your travel plans with ease. Just stay patient and persistent – with the right troubleshooting, error code 503999999 can be defeated. Happy travels!

Leave a Comment