Error Codes of STS Prepayment Meters

STS (Standard Transfer Specification) prepayment meters take digital medium as information exchange media. Users load in pre-purchased credit and then the meters take credit as their billing to realize the functions of active energy measuring and prepayment control and realize remote communication and remote control via module.
Local power companies or utilities use prepayment meters to avoid debts by charging power bills in advance. Additionally, prepayment smart meters with automatic reading function reduces cost of manual collecting meter data.
For end-customers, they can check their meter load in real time to use power reasonably. They can also recharge meters in any place and any time, instead of going to local power company to pay for.

CLOU STS Prepayment Meters

We have many STS prepayment meters, such as CL730S22 and CL710K22. You can also find more information about prepayment meters here.

Single Phase Meter CL710K22
Single Phase Meter CL710K22
Three Phase Meter CL730S22
Three Phase Meter CL730S22

Differences between TOKEN and Meter Numbers

TOKEN numbers and meter numbers are two totally different things.
According to the STS standard, a TOKEN has only complete 20 digits.
While CLOU STS meters have 11 digits. Other CLOU meters also have 12 digits.
The length of meter numbers is customized.
When you input a Token by which the prepayment meter can not work, the meter will show error codes. Specific reasons are cited one by one as below. If your meter equips an UIU (User Interface Unit), error codes also shows on its LCD.

Error Codes Shown on CLOU Prepayment Meter

CLOU regulates prepayment meter error codes in a certain statement according to the IEC62055-41 chapter 7.1. Almost all CLOU prepayment meters have the same error codes.
Here takes error codes shown on the CL730S22 three-phase meter as an example.

Meter Display Information

  • OPEN Any meter cover was opened
  • DISTU Magnetic disturbance detected
  • OVER PO Power exceeds the limit
  • VOL-OVER Voltage is over allowed threshold
  • CUR-OVER Current is over allowed threshold
  • CUR-UNB Current unbanlance occured
  • N-DST Neutral line is disturbed
  • CT-BYPAS Meter is bypassed
  • CT-OPEN Meter current circuit is open
  • VOL-UNB Voltage is unbalanced
  • HIGH-TMP Temperature too high
  • LOW-PF Power factor too low

UIU Display Information

  • ACCEPT TOKEN accepted
  • REJECT TOKEN rejected. The 20-digit TOKEN input is not generated from the designated platform.
  • OLD TOKEN expired
  • USED TOKEN used
  • FULL Overflow error. The credit register in the payment meter would overflow if the token were to be accepted; the token is not accepted.
  • OK Operation accepted
  • Err_01 Error in manufacturer code. The Manufacturer Code value in the Class 1 token does not match the Manufacturer Code value for the Decoder.
  • Err_02 Key expired error. The TID (Token Identifier) value as record in the token is larger than the KEN (Key Expiry Number)stored in the payment meter memory.
    Solution: First, please check your meter KEN value if it has expansion space or not; If the number is already maximum, shift the TID and change the Base Date in the energy selling system into “2014” option.
  • Err_03 DDTK (Decoder Default Transfer Key) error. The Decoder has a DDTK value in the DKR (Decoder Key Register): a Transfer Credit token may not be processed by the Meter Application Process in accordance with the values given in credit.
  • Err_04 Overflow error. The credit register in the payment meter would overflow if the token were to be accepted; the token is not accepted. (Some meter types are showing Err_04 instead of FULL).
  • Err_05 Key type error. The key may not be changed to this type in accordance with the key change rules.
  • Err_06 TOKEN format error. One or more data elements in the token does not comply with the required format for that element. That’s say, to aviod this error, 20 digits of the TOKEN are correct and complete, and the TOKEN must be valid and unused. For example, the error shows when one only inputs 19 digits.
  • Err_07 TOKEN range error. One or more data elements in the token have a value that is outside the defined range of values defined in the application for that elements.
  • Err_08 TOKEN Function error. The particular function to execute the token is not available.
  • NULL Reserved

Troubleshooting to Pairing A UIU with A Meter

If something wrong happens while paring a UIU (User Interface Unit) with an energy meter, the following steps can be taken to initiate the UIU for troubleshooting.

  • Step1: Input “1593570” + “999” + “Enter” to initialize the UIU.
  • Step2: Input “1593570” + “11-digit meter number” + “Enter” to pair the meter with UIU.
  • Step3: Input “999” + “enter” to check the paired meter, and “12-digit address” will be displayed on the UIU.


So far, we have received a great number of comments about meter error codes and TOKEN. This article aims to at least provide a fundamental explanation to error codes.
For visitors who are finding information about them, wish this article can help you.
If you have more questions about error codes, just leave a comment below to discuss it.
Thank you for your reading and best wishes.

Editor's note: This article was originally published in November 2021 and has been updated for comprehensiveness.

86 Replies to “Error Codes of STS Prepayment Meters”
  1. Please I will really appreciate if I can get help.. my memmcol single face meter is showing error 06 while trying to load token bought from my bank app.. tho have recharge it once through the bank app but I really don’t know why it’s showing error 06 now when loading token..

    1. Thank you for your question. Regarding the error 06 on your Memmcol single-phase meter, it’s important to note that different meter manufacturers may have different error code meanings and definitions. In the case of CLOU meters, the meaning of error 06 is explained in an article. However, since you have a Memmcol meter, it would be best to reach out to your local power supply company or the manufacturer of your meter for specific details and assistance regarding the error code. They will be able to provide you with the most accurate information and guidance to resolve the issue.

    1. Thank you for taking the time to read and for your thoughtful comment. Your words are truly appreciated.

  2. Hello. We been faced with a problem with the Clou meter CL710K11. On the Keypad, we able to check balance of the remaining electricity units but when we dial to input token, it displays “reject”. At first we thought we made an error in the digits but no, every digit is okay but still the message “reject” displays. Is there a code to correct this error? Any solution is highly appreciated.

    1. The message ‘reject’ indicates that the token was either generated by an unauthorized system or not for your meter. I suggest, you show the token to your energy vendor. They can check. Most likely, they made a mistake.

    1. The message indicates that the opened cover was leading to the tamper situation. It will vanish once a valid ‘clear tamper’ token is entered.

  3. Please my wallet get lost nd my meter number is there how can I get it through my meter box. What is d code

    1. The CLOU default UIU code to retrieve the meter number is 009. This can have been altered on utility request.
      Alternative, you can read the printed number on the meter.
      The vending station operators can also find the number by your customer name or contract ID.

  4. They bought a New Meter to my apartment and I wanna know the remaining balance in the meter.. I dialed the code on the Keypad but it not showing the remaining balance.. Or is there a code I need to dial first before I can check the balance on my Prepaid meter.. Please I need help

    1. The user interface unit (UIU) need most likely to be paired. How to do that is described in the article.

    1. As long as you have power at home, there is no bypass. If you have a tamper indication on the UIU and no power, your utility has the tools to read out the tamper log. Then they can tell you the cause (e.g. bypass).

  5. I didn’t enter the token the day I bought it until today and it’s displaying used. Why?

    1. STS prepaid meters keep records of all tokens that have been entered. If you try to enter the same token again, it shows “Used”. Your power company can read out the information, on which date the token was used.

  6. No electricity in my apartment since i install clou prepayment meter. What do i do to change my minimum voltage to something like 90V . Please help

    1. Your power company or utility can change the minimum voltage threshold via optical port programming. Nevertheless, it’s a security feature for your home appliances. If you have permanent too low voltages, it’s better to let the utility change the distribution transformer voltage tapping.

  7. My clou meter is not opened and the seal is intact but the relay is opened. Some few months ago i had the same problem and I was given a code that closed the relay but I’ve forgotten. Can u pls help me out?

    1. The given code from your utility is always a one-time-use code. No need to remember, it will not work twice. You need to ask your utility for a new code. Only they have the possibility to do that.

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