Wrong Signature Type — ITAX vs DIGITAL
This is the most common eTIMS rejection reason, accounting for roughly 40-50% of all rejected invoices. When you create an invoice in eTIMS, you must select the correct signature type for your customer.
| Signature Type | Who It Is For | When to Use |
|---|---|---|
| ITAX | VAT-registered businesses and organisations | The customer needs your invoice to claim input VAT. They have a VAT PIN and file VAT returns. |
| DIGITAL | Individual consumers, non-VAT businesses, and anyone not registered for VAT | The customer is not claiming input VAT. They do not have a VAT PIN or are below the registration threshold. |
You selected ITAX for a consumer customer
If you sell to individual consumers (e.g. retail customers, walk-in clients), they do not have a VAT PIN. Always select DIGITAL for non-VAT customers.
You selected DIGITAL for a VAT-registered customer
If a customer asks for your KRA PIN and says they need the invoice for their VAT return, they are an ITAX customer. Selecting DIGITAL means their purchase will not appear in their eTIMS purchase register.
When in doubt, ask the customer
Simply ask: 'Do you need this invoice for your VAT return?' If yes, use ITAX. If no or unsure, use DIGITAL. You can also look up a customer's VAT status on iTax by entering their KRA PIN.
Duplicate Invoice Serial Number
eTIMS assigns a unique serial number to every invoice. If you try to use a serial number that has already been used (including on a cancelled or rejected invoice), the system will reject it.
Find the last successfully issued invoice number
Go to your eTIMS dashboard and look at 'Issued Invoices'. Note the last serial number that was successfully issued. The next invoice should use the next sequential number.
Check for gaps caused by cancelled or rejected invoices
When an invoice is cancelled or rejected, its serial number cannot be reused. The system automatically skips it. If you are trying to use a number from a cancelled invoice, the system will reject it as a duplicate.
Reset your serial number range if needed
If you have exhausted your serial number range or the numbering has become corrupted, contact KRA eTIMS support to reset your serial number range. This is uncommon but happens.
Do not try to override or reuse serial numbers
Each serial number can only be used once. Trying to force a duplicate serial number will not work. Always let eTIMS auto-assign the next number.
Customer KRA PIN Validation Failed
When you enter a customer's KRA PIN on an ITAX invoice, eTIMS validates it against KRA's database. If the PIN is invalid, inactive, or does not exist, the invoice will be rejected.
PIN format may be incorrect
KRA PINs follow the format A0123456789Z — 11 characters, all uppercase, no spaces. Check for common typos: O vs 0, I vs 1, S vs 5.
Customer's PIN may be deactivated or suspended
If the customer's PIN has been deactivated by KRA (for non-compliance or other reasons), eTIMS will not accept it. Ask the customer to check their PIN status.
Customer gave you the wrong PIN
Some customers may not know their own KRA PIN or may give you an old one. Ask them to verify their PIN on iTax or check their KRA PIN certificate.
Switch to DIGITAL if the customer does not need input VAT
If the customer's PIN is not working and they do not urgently need to claim input VAT, select DIGITAL instead. This bypasses PIN validation entirely.
Control Unit Error / Connection Timeout
eTIMS relies on either a physical control unit (ESD — Electronic Signature Device) or the online portal to sign and transmit invoices. If the control unit or connection fails, invoices get rejected.
Check your internet connection
The eTIMS online portal requires a stable internet connection. If your connection drops during invoice submission, the invoice may be rejected. Ensure you have at least 2 Mbps connectivity.
Restart the eTIMS control unit (ESD)
If you use a physical ESD device, try restarting it. Unplug the device, wait 30 seconds, and plug it back in. Wait for the device to fully initialise before issuing a new invoice.
Update your eTIMS software or firmware
Outdated eTIMS applications or ESD firmware can cause communication errors. Check for updates on the eTIMS portal or contact KRA eTIMS support for the latest version.
Contact KRA eTIMS support if hardware is faulty
If your ESD device is physically damaged or malfunctioning, contact KRA at etims@kra.go.ke or call 020 4 999 999. You may need a replacement device.
Keep a log of system failures
If your eTIMS system is repeatedly failing, take screenshots and note the date/time of each failure. KRA may issue penalties for non-compliance even during system downtime, but having evidence of the fault strengthens your case for a waiver.
Invoice Amount Mismatch
eTIMS validates that the invoice total matches the sum of line item amounts. If there is a discrepancy of even one cent, the invoice will be rejected.
Check line item totals add up to the invoice total
The most basic check. Add up all line item amounts (quantity × unit price) and confirm they equal the invoice total. Rounding differences can cause rejection.
VAT calculation must be exact
The VAT amount on the invoice must equal exactly 16% of the taxable value. eTIMS calculates this automatically, but if you override the VAT amount manually, it must match precisely.
Discounts must be applied correctly
If you apply a discount, eTIMS expects it to be reflected in the line item amounts. You cannot show a gross total and a discount separately — the line items must reflect the discounted price.
Currency rounding issues
eTIMS works in whole Kenya shillings (KES) or with two decimal places depending on your setup. Inconsistent decimal usage across line items can trigger rejection.
Item Description or HS Code Errors
eTIMS requires each line item to have a valid description and, in some cases, a correct HS (Harmonized System) code. Errors in these fields are a common but easily fixed rejection cause.
Item description is too vague
Descriptions like 'goods', 'services', or 'miscellaneous' may be rejected. Use specific descriptions: 'Laptop computer Dell XPS 15', 'Office cleaning services March 2026'.
HS code is missing or incorrect
Some VAT categories require HS codes. If your products are zero-rated or exempt, the correct HS code is essential. Find the right HS code on the KRA website or iTax portal.
Tax rate does not match the HS code
If your HS code indicates a 0% rate but you enter 16% VAT (or vice versa), eTIMS will reject the invoice. Ensure the tax rate matches the HS code classification.
Unit of measure mismatch
If you specify 'pieces' but the HS code expects 'kilograms' or 'litres', eTIMS may reject. Use the standard unit of measure for your product type.
How to Cancel and Reissue a Rejected Invoice
You cannot edit a rejected eTIMS invoice. The only way to correct it is to cancel the rejected invoice and create a new one. Here is the exact process.
Cancel the rejected invoice in eTIMS
Go to 'Issued Invoices', find the rejected invoice, and select 'Cancel'. Enter a cancellation reason (e.g. 'Wrong signature type, re-issuing').
Note the rejection reason
Before creating the new invoice, make sure you understand why the original was rejected. Refer to the relevant section in this guide for the fix.
Create a new invoice with a fresh serial number
The old serial number is now unusable. Create a new invoice and eTIMS will assign the next available serial number automatically.
Double-check all fields before submitting
Verify: signature type (ITAX/DIGITAL), customer PIN (if ITAX), line item amounts, VAT calculation, item descriptions, and HS codes. One mistake means starting over.
Confirm the new invoice is accepted
After submission, check that the invoice appears in 'Issued Invoices' with a 'Success' or 'Accepted' status. If it is rejected again, check the new rejection reason.
Prevention: Stop Getting Rejected Invoices
The best fix for a rejected invoice is to never get one in the first place. Here is a pre-flight checklist to run before every eTIMS invoice submission.
- Confirm the customer type: VAT-registered business (ITAX) or consumer (DIGITAL).
- If ITAX, verify the customer's KRA PIN on iTax before entering it into eTIMS.
- Ensure the serial number is the next available — let eTIMS auto-assign it.
- Double-check line item totals add up to the invoice total exactly.
- Verify VAT is calculated at exactly 16% (or the correct rate for zero-rated/exempt items).
- Use specific item descriptions — no vague terms like 'goods' or 'services'.
- Check that HS codes (if required) are correct and match the tax rate.
- Ensure your eTIMS device or portal connection is working before you start.
- Have a stable internet connection throughout the submission process.
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Start eTIMS Management — KES 2,500/monthFrequently Asked Questions
- Why does eTIMS keep rejecting my invoices?
- The most common reasons are: (1) Wrong signature type — you selected ITAX but the customer is a DIGITAL user, or vice versa. (2) Duplicate invoice serial number — the number has already been used. (3) Customer's KRA PIN is invalid or not found. (4) Control unit malfunction or connection timeout. (5) Invoice total does not match the line item breakdown. Check the rejection message carefully — eTIMS usually tells you exactly what is wrong.
- What is the difference between ITAX and DIGITAL signatures in eTIMS?
- ITAX signature means the customer is a VAT-registered business that files returns on iTax and will claim input VAT on your invoice. DIGITAL signature means the customer is not VAT-registered (e.g. an individual consumer or a non-VAT business). Selecting the wrong signature type is the most common cause of invoice rejection. If your customer is an ordinary consumer, always select DIGITAL.
- Can I edit a rejected eTIMS invoice and resubmit it?
- No. Rejected invoices cannot be edited. You must cancel the rejected invoice in the eTIMS system and create a new one with a fresh serial number. The old serial number cannot be reused. Always double-check your entries before submitting to avoid wasting serial numbers.
- How do I fix a duplicate invoice number error in eTIMS?
- A duplicate serial number error means that number has already been used in the system. eTIMS assigns serial numbers sequentially. If you are getting this error, check: (1) You may have skipped a number — find the last successfully issued invoice and continue from the next number. (2) The serial number was already used in a draft or cancelled invoice. (3) Your eTIMS device serial number range needs resetting — contact KRA eTIMS support.
- What should I do if my eTIMS control unit stops working?
- If your eTIMS control unit (the physical device or software) fails, you cannot issue compliant invoices until it is fixed. Contact KRA eTIMS support immediately on 020 4 999 999 or etims@kra.go.ke. In the meantime, issue manual pro-forma invoices and note that they will be entered into eTIMS once the system is restored. KRA allows a grace period for system failures, but you must have evidence of the fault.