Technical FAQs - TWS


Where I can see the TWS system requirements?
Minimum and recommended systems requirements for supported operating systems are listed here. To ensure that you have an adequate Internet connection and enough system resources to run TWS, we recommend that you first open a Trial Account and test the platform.
What are the connectivity requirements to run TWS?
The list of servers which need to be reachable from your machine for operating the TWS are available in the section "DESKTOP TWS" of KB2816.
Can I perform a connectivity test before running the TWS?
It is possible to verify if your computer can reach the needed servers following the instructions on KB2807.
Do I need to install Java before installing or running the TWS?
You do not need to download or install Java manually. The Java Runtime Environment used by TWS is deployed automatically to your machine during the TWS installation.
How do I install the TWS?
The installer packages and related instructions can be found on the Installation Instructions page.
In which cases I should use the OFFLINE version of the TWS?
If you have a slower Internet connection or a restrictive firewall / security system, you may use the OFFLINE version of TWS. This version already packages all the needed core application files in the installer and does not need to download any additional component during the installation. Moreover, this version will not perform automatic platform updates during the start-up phase. Please notice that a working Internet connection and network access to our servers is still required in order to run the OFFLINE TWS, as described in the section "DESKTOP TWS" of KB2816.
What is a BETA release, and how can I use it?
The beta release is a pre-production version of an upcoming release that allows you to actively trade while you test new features. You must deliberately elect to use the beta when you log in and should be aware that you do so at your own risk. Since the beta is under construction until production release, we welcome your input on its performance. The beta will be promoted to production after it has been tested both in-house and externally over a specified time period.
How will I know when a new TWS version has been released?
The TWS update wizard will automatically check for TWS updates each time you log in to the platform. 
Note: The OFFLINE version of TWS will not perform the automatic update. Should you want to update the OFFLINE TWS platform, you need to download and run again the TWS OFFLINE installer.
How do I know what changes are in a new TWS release?
The login page includes links to both the beta and production release notes. These notes briefly describe new features and problems that have been fixed.
Where can I find more information and guidance about the TWS?
Instant help resources include the TWS Webinars, TWS Release Notes, TWS User's Guide, and the Online Tutorials. If you still cannot find an answer to your question, you can contact our Client Services.
How do I reinstall the TWS?
First, remove the TWS software from your machine using your operating system uninstall facility (usually present within the System Settings or within the Control Panel). You can then download and install the TWS again following the instructions on the TWS Software page.
Why are my credentials rejected during login?
You will receive this message for one of the following reasons:
- you are not entering the proper username (check to be sure the Caps Lock key isn't on)
- your account has not been set up yet
- you've entered your password incorrectly more than 10 times
Can I have multiple TWS instances running simultaneously with the same username?
A username can only have one session running at a given time. If your username starts an additional trading session, the system will ask you to disconnect the previous one. In order to run multiple trading sessions, you would need to create additional usernames as described in KB1004.
Can I copy the TWS layout of a given user to another one?
Yes. The procedure is described in KB2320.
On my Mac machine I cannot launch two instances of the TWS. Is there anything I can do?
This is a limitation of the MacOS system but two workarounds are available and detailed in KB2637.
When I install the TWS, the installer tells me that it cannot write a file. What should I do?
This is usually due to wrong / missing filesystem permissions of your user not having the rights to install software. You may try to SHIFT + right click on the TWS installer and select Run as Administrator. If this does not help, we suggest you contact your IT support or your local PC support and have them install the TWS for you.
When I install the TWS, I receive the error "The signature of the file is corrupt or invalid"
This is usually due to the Microsoft signature validation system and can be solved following the instructions on KB2635.
When I try to install the TWS on my Mac machine, I receive the error "TWS installer is damaged and can't be opened. You should eject the disk image." How can I fix this?
This is usually due to the installer package not being digitally signed by Apple. In order to bypass this check, go to your Mac OS System Preferences by clicking on the Apple icon on the top left corner of Screen and on System Preferences. Click then on "Security and Privacy". Make sure you are in the tab: General and set radio button for "Allow apps downloaded from" to "Anywhere". Launch again the TWS installation. It should now complete fine. Once you have installed the TWS, please go back to the Security and Privacy system preferences and set back the radio button on "Mac App Store and identified developers" since letting it to "Anywhere" represents a security risk.
When I start the TWS I receive the error message "Download Settings from server failed". What can I do?
This is most probably due to the setup of your network. The troubleshooting procedure is described KB3146.
When the TWS starts up I receive the error "Update failed, Retry? Cancel?" How can I fix this?
This may happen if your firewall / security system limits or blocks access to the IBKR update servers. Please consider the TWS connectivity requirements described in the section "DESKTOP TWS" of KB2816.
When I start the TWS I receive the error message "Ddedll.dll file missing or out of date". How can I overcome this?
This error is shown when you try to enable the DDE API access on a 64-bit TWS instance. The steps for the resolutions are indicated in KB2155.
When I start the TWS I receive the error message "Could not create the Java Virtual Machine". What can I do?
This error may be displayed upon TWS startup if you set the memory allocation for the TWS to a value higher than the available RAM of your system or if you set it higher than 2048 Mb on a 32-bit Operating System. To overcome the error, you would need to decrease the memory allocation to a lower value, as explained in this KB2170 procedure.
Can I use the TWS on a network where the IPv6 protocol has priority over the IPv4?
Yes, you just need to open the C:\Jts\jts.ini file and, below the line ###Keep on update, add the following line:
Once done, save and close the file and start again the TWS.
My TWS platform freezes or crashes often. What can I do to improve the situation?
Normally the TWS needs to allocate and use around 1GB of free memory(RAM) on your machine. If your TWS layout is complex or includes many tools, charts, windows, the standard memory allocation may not be sufficient. This may cause the TWS to freeze or crash. The situation can be improved by assigning more system memory to the TWS, as explained in KB2170.
When I launch the TWS installer on my Mac machine, I receive a warning message. What should I do?
Please check for possible scenarios and related instructions.
I want to use the TWS from a corporate machine but, upon login, I receive reconnection attempts messages and the platform seems unable to connect to the IBKR servers. How can I solve this?

Corporate environment have usually restrictive firewall rules which may limit or block access to external resources. In order to run the TWS in such environments, you would need to contact your IT / Networking department and have them consider the TWS connectivity requirements described in the section "DESKTOP TWS" of KB2816.

I use the TWS on multiple computer and I would like to have the same platform layout on all of them. Is it possible?
The TWS settings of a given user can be synchronized across multiple computer. The steps to enable this function are described in KB2282.
Who do I contact in case I experience technical issues with TWS?
IBKR has two distinct departments that handle specific types of TWS questions. The Client Services deals with everything involving trading, accounts, funding and executions while the Technical Assistance Center (TAC) can help you with connectivity and platform issues.
Should you require immediate help, please call directly our Client Services. We recommend you to:
- call while you are experiencing the problem
- have your computer turned on and ready for the troubleshooting
- have your account information at hand
If your case does not require immediate attention, we advise you to open a Chat with us, ask iBot or submit your inquiry via Message Center ticket. Should you not have access to your Client Portal, you can use the Contact IBKR facility.
In any case, please be ready to provide:
- your username or account number
- a detailed explanation of the problem
- the time-frame during which the problem has occurred or occurs.
- any pattern you have noticed (e.g. the issue surfaced after the last update, the issue surfaces only when market is closed...)
- your operating system and browser (when applicable)


TWS Message: Order price relative to the market.

The TWS contains two checks to limit the possibility of clients entering trades at prices which are substantially inconsistent with that of the current market. 

Under the first check, stock buy orders which are 10% above the prevailing NBBO ask price will be automatically rejected by IBKR as will stock sell orders which are 10% below the prevailing NBBO bid price.  In the case of options, IBKR's automatic rejection threshold percentage for both buy and sell orders is 20%.  When an order violating these parameters is transmitted, it will be rejected and a TWS pop-up window will be displayed with the following warning message: "Limit price too far outside NBBO" or "This order is not accepted.  The limit price cannot be more than 10% through the NBBO.".

The second check relates to orders which are transmitted at prices which do not violate the parameters set by IBKR as outlined above, but which do violate parameters established by the account holder.  Here the account holder is able to establish Precautionary Settings by selecting the Order and then Configure Order Presets menu options from the TWS. This will open up a window providing for the creation of price thresholds set in terms of percentage or the number of ticks outside of the NBBO (settings may also be defined in terms of share/contract quantity or total dollar value of trade).  When an order violating the account holder's parameters is transmitted, it will be rejected and a TWS pop-up window will be displayed with the following warning message: "The price specified would violate the percentage constraint specified in the default order settings.  Do you really want to submit this order?"  Unlike in the case of the check set by IBKR, the account holder has the option of overriding their own settings and transmitting the order by clicking on the "Yes" button.


Glossary terms: 

How can I trade stocks during the pre-market or post market?


By default, orders for some products are entered with a restriction referred to as Regular Trading Hours (RTH) Only.  This restriction may prevent submitted orders from executing during the pre and post market sessions.  The following article will clarify this time restriction as well as how it can be modified.



There are risks inherent in trading outside of Regular Trading Hours (RTH) including reduced liquidity, increased volatility, and expanded error trade guidelines  that traders should be aware of and willing to assume prior to transmitting active orders into the market during these times.



How to determine if a submitted order has a RTH restriction applied.

Changing Default Settings

Other Important Notes


How to determine if a submitted order has a RTH restriction applied.


Trader Workstation (TWS)

Orders restricted to RTH only will display a clock icon in the Time in Force (TIF) field.

Hold your mouse over the clock icon to display information regarding when the order can be filled.


Orders without a time restriction will either display no clock icon or will display the clock icon with an exclamation point over it to indicate that it will be active outside of the regular trading session.


Traders may change the RTH setting by clicking this field before the order has been transmitted.  From the dropdown that appears, check the box that says "Fill outside RTH".


Web Trader

The Create Order window in the Web Trader displays a checkbox that says "Fill Outside Regular Trading Hour".  If this box is grayed out, it indicates that the RTH setting is not applicable for the default order type.



IBKR Mobile

To check to see if your order is eligible to fill outside of regular trading hours, go to the Orders & Trades tab (iOS) or the Orders tab (Android) and tap on the order in question. If using the iOS app, there will be a line item stating if the order is eligible to fill outside of regular trading hours:

If using the Android app, there will be a line item for Time-in-force. Click the small arrow on the right side to expand the section. There will be a line item for Outside RTH with a toggle that will be set to ON (eligible to fill outside RTH) or OFF (not eligible to fill outside RTH).

Clients can set their order to fill outside regular trading hours through the IBKR Mobile Order Ticket. In both the iOS and Android versions of IBKR Mobile, the Order Ticket will have a line item where you can toggle Outside RTH on or off. Once you have made your election, fill out the remainder of the Order Ticket and submit when ready.



Note:  The RTH restriction cannot be modified once an order has been transmitted.  In order to change the RTH restriction the submitted order must be canceled and a new order entered with the appropriate RTH selection.

Changing Default Settings


Web Trader

The web trader does not support saving of default order types and configurations.  As a result, traders must select the RTH option for each order created if the intention is for it to be active outside of the regular trading session.


Trader Workstation (TWS)

Traders can adjust the default RTH setting in the TWS as follows;

1.  Select the Edit menu followed by Global Configuration at the top of the main TWS screen. 


2. On the left side of the window that appears, click the "+" next to the word Presets to expand the section.


2.  Next, select the product type (Stocks, Futures, etc.) by clicking on the word so that it is highlighted.


3.  In the Primary Order section, be sure the Order Type is set to LMT. (if MKT or STP is set as the default the RTH setting will not be applicable).


4.  In the Timing section, check the box that says "Allow order to be activated, triggered, or filled outside of regular trading hours".


5.  Click Apply and then OK at the bottom of the window.

6.  Orders that support modification of the RTH restriction (for the product selected in step #1) will be created with the new default applied.


IBKR Mobile

Traders can adjust the default RTH setting in IBKR Mobile (iOS or Android) as follows;

  1. Tap the menu (More) button and select Configuration    
  2. Look for the Cloud section and tap Trading Settings                 
  3. Tap the Product that you wish to edit the Presets for                          
  4. Tap the Timing line item                                                              
  5. Toggle Outside RTH on or off. Once finished simply tap the back button to save your changes to the Cloud.                    


Other Important Notes:


* Traders unfamiliar with the Regular Trading Hours for a particular product may right click on the market data line and choose Contract Info followed by Description.  This window will list the Regular Trading Hours for the selected product.

* Forex, OTCBB, and Pink Sheet securities do not have a Regular Trading Hours designation as there is no centralized marketplace or primary exchange.  Traders should use caution when trading these products during the early and late sessions as orders will execute regardless of any default RTH restriction previously applied.

* Outside Regular Trading Hours for IBKR Pro accounts begins at 4:00 EST and lasts until market open, and restarts at market close until 20:00 EST. Outside Regular Trading Hours for IBKR Lite accounts begins at 7:00 EST and lasts until market open, and restarts at market close until 20:00 EST. Regular Trading Hours for both account types are 9:30-16:00 EST.

* For stocks, Market orders and Stop orders (which, when triggered, become Market orders) are only active from 09:30 until 16:00 EST (the Nyse's regular trading hours session). To have the order active in all sessions including the Premarket hours, Regular Trading Hours and the Aftermarket hours, you must use a Limit or Stop Limit type order and add the attribute "Allow Outside RTH". The same settings apply for Globex/ECBOT/Nymex Future contracts. The Nybot accepts Stop orders and converts them internally to "Stop with Protection" orders that are active for all available hours. A Future contract's RTH session is detailed in the contract's description window.


Is there a training manual for the Trader Workstation?


Yes, IBKR provides a Users' Guide for the Trader Workstation (and also the Web Trader).  This Users' Guide can be found on the website via the Education > Documentation menu item.


You can access the TWS User's Guide at the following link: TWS User's Guide.  There is also a printable version available but be aware that it is very long should you decide to print it out.  Once the online guide is loaded, you can navigate through the guide with the "Contents" or "Index" tabs.  For quick access to information on a particular issue you can use the Search button found at the top of the page.

How do I enter the symbol for Berkshire Hathaway Class B shares onto TWS?


There are a variety of symbol conventions for denoting Berkshire Hathaway Class B shares (CUSIP 084670207). On the IBKR trading platforms, this security is designated by entering BRK, then a space and then B (BRK B). This compares to Bloomberg which uses the convention BRK/B and Yahoo Finance which uses BRK-B.

It should also be noted that this security has been designated as a 10-share unit issue by its primary listing exchange, NYSE Arca, due to its relatively low trading volume. A round lot in this security is therefore set at 10 shares as opposed to the standard round lot unit of 100 shares. If your opening buy or sell order is for an amount less than 10 shares, it is considered an odd-lot and subject to  special handling considerations. Please review our website under the Trading and then Order Types menu options for additional details.

How do I add the field OCA Group to my Trader Workstation trading page?


Towards the top right corner of the TWS Order Management Screen, you will see a "Trader Workstation/Ticker Lookup" search field.  Immediately to the left of this you will see a wrench shaped icon.  Click the icon.  From here, click on the Order Columns tab from the TWS Configuration window.  On the right side under Available Columns, click on Order Attributes to expand that selection and see all of your choices.  Click on OCA Group so that it is highlighted.  Then click on the Add button.  This will add OCA Group to the Shown Columns list.  Now click on the Apply button at the bottom of the window, and then the OK button.  The OCA Group column should now be on your TWS Order Management page.

Note: Because the OCA procedure is an automated process, there is no guarantee that requested cancellations and modifications will reach the specific exchange before an order has been executed.

The P&L in my Account Window does not match the P&L displayed on the Trader Workstation.


Please note that both Realized and Unrealized P&L on Trader Workstation are for informational purposes only.  They neither add, nor subtract, anything from your account.  The actual P&L credited to or debited from the account is computed from the opening trade price to the closing trade price.  This information can always be found in the daily activity statement for the account.  The P&L values displayed use the market price value when computing the value that is being displayed.  The system gives less weight to pre and post market transactions due to the lack of liquidity and the width of the spreads.  As a result of this, the previous close is used until the NYSE market opens at 09:30 EST.



The Account Window utilizes the following formulas to calculate P&L:  Unrealized P&L is the difference between the current market value of your open positions and the average cost, or Value – Average Cost; Realized P&L shows your profit on closed positions, which is the difference between your entry execution cost and exit execution cost, or (execution price + commissions to open the position) – (execution price + commissions to close the position). 


The Order Management page on TWS utilizes two different P&L calculation methods.  It is for the account holder to decide which calculation method they wish to have displayed:  Daily P&L is calculated for all positions you currently hold using the new position calculation and the formula (current price) – (prior day’s closing price) x (total number of outstanding shares); while New Position P&L is calculated for transactions executed today using the formula (current price) – (purchase price) x (number of outstanding shares purchased today).

How can I close my open positions in the event my Internet connection is disrupted?

IB maintains a trade order desk within each of its US, European and Asian Customer Service Centers, effectively providing 24 hour support for phone orders.  Traders should note that the order desk facilitates closing market orders only and such orders are assessed a Telephone Order fee of USD 30, or equivalent, in addition to all regular commissions.  A listing of phone numbers for each of the Service Centers which we recommend you print and maintain in the event you experience an Internet outage may be found here

How, under the Windows operating system, do I create a screen shot to send to IBKR?


For some support related issues, obtaining a screenshot may provide valuable information that will assist us with resolving the issue being experienced.  The following page describes two different methods of creating a screenshot. 

Manual Screenshot

For traders not using the TWS, the following describes the process of creating a screenshot and attaching it to a web ticket to submit to Client Service.

To provide an image of your full computer screen  select and hold down the ‘Ctrl’ key and then the ’Print Screen‘ key (located in the upper right corner of the keyboard).

For an image of a single window within your screen select and hold down the ‘Alt’ key and then the ‘Print Screen’ key   

Next, open a text or image editing program such as Microsoft Word to ‘paste’ and save the shot you’ve just created.  Once the program has opened select and hold down the 'Ctrl' key and then hit the “V” key. Verify that this is the image you wish to send and then save the document to your computer.  Log in to Advisor Portal and select the Message Center from where you can create a new web ticket and attach your document.


TWS Screenshot / Log File

Traders using the TWS software can use keyboard combinations to capture snapshots of their screen and upload them to assist with support issues.

To create a snapshot of the TWS screen and upload the log file please use the keyboard combination associated with the type of machine being used;

  • All PC's except HP's: Ctrl+Alt+H
  • Hewlet Packards (HP): Ctrl+Alt+Q
  • Mac: Ctrl+Option+H

A window will appear allowing the trader to enter text and check the screenshot box to include an image of the computer screen.

After pressing submit, the following window will appear to acknowledge that the files have been uploaded.



  • Client Service does not monitor these uploads during the day so be sure to communicate with the Client Service desk prior to uploading files relating to a current issue.
  • Traders behind a firewall or proxy may be unable to upload log files and screenshots using the TWS method.

How can I request for a replacement secure login device or temporary security code?

IBKR is committed to protecting your account and your account assets from fraudulent practices. The Secure Login System provides an extra layer of security to your account. For security purposes, all replacement security device requests must be addressed via telephone and only after the identity of the named account holder or authorized user has been verbally verified. For assistance in accessing your account immediately and obtaining a replacement security device, please contact IBKR Client Services via telephone to restore login access.


  • See KB69 for information about Temporary passcode validity
  • See KB1131 for an overview of the Secure Login System
  • See KB2636 for information and procedures related to Security Devices
  • See KB2481 for instructions about sharing the Security Login Device between two or more users
  • See KB2545 for instructions on how to opt back in to the Secure Login System
  • See KB975 for instructions on how to return your security device to IB
  • See KB2260 for instructions on activating the IB Key authentication via IBKR Mobile
  • See KB2895 for information about Multiple 2Factor System (M2FS)
  • See KB1861 for information about charges or expenses associated with the security devices


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