Meera's new client sent a purchase order, a vendor form, and one line that changed the whole invoice: "Invoices without a valid GSTIN and correct place of supply will be returned unpaid."

She had entered her own GST details. The customer's details were another matter.

The usual way to do this  

Covered in our published Taxes FAQ, with your own registration in Taxes (Settings) and your customer's details in Customer Details.

Start with the two sides separately.

Your business:

1. Go to Settings → Taxes.

2. Enter your GST registration details, including your GSTIN and registration date where required.

3. Enter the state associated with the registration.

4. Save the changes.

5. Create a test invoice and check which tax is being applied.

Your customer:

1. Go to Customers.

2. Select the customer.

3. Click Edit.

4. Open the Other Details or tax-information section.

5. Select the appropriate GST treatment.

6. Enter the customer's GSTIN if they are registered.

7. Select the customer's Place of Supply.

8. Save the customer.

9. Create a fresh invoice for that customer and check the tax calculation.

The point is to get the customer record right once rather than correcting GST details on every invoice. Zoho's current customer GST instructions likewise put GST treatment, GSTIN and Place of Supply on the customer record.

But your case may be different  

You may be facing one of these:

• The GSTIN auto-fetch returns nothing

• A GSTIN will not save

• I can no longer change my tax registration or state

• I need e-way bills

• I have been told I fall under the e-invoicing mandate

Working through it  

The GSTIN auto-fetch returns nothing

The lookup depends on the government GST portal being reachable.

If the lookup fails, do not immediately assume your Zoho Invoice setup is wrong.

Try this:

1. Check the GSTIN you entered for spaces or typing errors.

2. Try the lookup again after a short while.

3. If it still does not return the details, enter the required information manually.

4. Save the customer.

5. Create a test invoice and check the GST treatment.

If the GSTIN itself is rejected or you are unable to save the customer details, check the GSTIN for typing errors and confirm that the GST treatment and required customer information are correctly configured. If the issue persists, contact Zoho Support or verify the GSTIN through the GST portal.

A GSTIN will not save

Check the number before changing anything else.

A GSTIN is 15 characters long. The first two digits represent the state code, and the characters that follow include the PAN.

The practical checks:

1. Copy the GSTIN into a plain text field first.

2. Remove any leading or trailing spaces.

3. Check the first two digits against the customer's state.

4. Check that you have not entered the letter O where the number 0 belongs.

5. Verify the GSTIN on the GST portal.

6. Return to Zoho Invoice and enter the verified number.

7. Save again.

If the verified number still fails, send the exact GSTIN to the support team rather than a screenshot where some characters are difficult to read.

I can no longer change my registration or state

If the fields are locked after you have already created transactions, do not try to work around the problem by creating another organization.

First:

1. Check whether the organization already contains issued transactions.

2. Confirm what registration or state information needs to change.

3. Check whether the change is a genuine business change or simply an initial setup mistake.

4. If the information is locked and the business information genuinely changed, contact support.

5. Keep the original organization and its transaction history intact while the change is being resolved.

The reason to be careful is simple: tax and location information can affect documents you have already issued.

I need e-way bills

First, separate the two requirements.

GST on an invoice is about calculating and displaying the applicable tax.

An e-way bill relates to the movement of goods and requires additional movement, dispatch and transporter information.

Zoho Invoice is designed for the core invoicing needs of small and mid-sized businesses, with a focus on simple invoice creation and management.

If you need to generate and manage e-way bills, this is a separate compliance workflow that Zoho Invoice does not fully support. Consider Zoho Books or Zoho Billing, which provide e-way bill capabilities along with broader GST compliance features.

Also check whether your business and the particular movement of goods fall under the current e-way bill requirements.

I have been told I fall under the e-invoicing mandate

Do not assume that "GST invoice" and "e-invoice" mean the same thing. Check the current applicability rules for your business, including turnover and transaction type.

On your phone: Customer GSTIN and Place of Supply can be edited in the app. Your organization's own tax registration setup is configuration work, so do that on the web before you start issuing invoices from the phone.

If It IS Still Not Right  

Work through these in order:

1. Check your own GST settings. Is your GSTIN and state correct?

2. Check the customer record. Is GST treatment, GSTIN and Place of Supply correct?

3. Check the state codes. Do the GSTIN and selected state agree?

4. Create a fresh invoice. Do not create a new setup only from an old draft.

5. Check the tax type. If you expected CGST + SGST but see IGST, or vice versa, check the place of supply.

Still stuck? Send support@zohoinvoice.com the invoice number, your GSTIN, the customer's GSTIN, and the tax breakdown you expected.

Over to you  

For Indian businesses here — what GST detail causes the most back-and-forth with your customers?