You log in the next morning, and the setup you finished yesterday is nowhere to be found. You are having a hard time finding your data. Here is where to look.
In this post
I logged in, and my data is gone. Where is it?
I set things up, but I am looking at a different Zoho app. What happened?
My verification code or OTP never arrives.
I no longer have access to the email address I signed up with.
Can I run two businesses from one login?

Missing data in Zoho Invoice is almost always one of these four things, in this order of likelihood.
I logged in, and my data is gone. Where is it? Start with the account, not the data.
Check the email address at the top right of the screen. If it is not the address you set up with, sign out and sign in with the right one.
If your email is correct, click on the Organization Name dropdown at the top right. Multiple organizations under one login are common, and a new empty one looks exactly like lost data.
Confirm you are in Zoho Invoice and not another Zoho app that shares your login.
Still nothing? Write to support@zohoinvoice.com from your registered email address. Nothing is deleted silently, so there is a record either way.
I set things up, but I am looking at a different Zoho app. What happened? Zoho Invoice and Zoho Billing/Zoho Books share the same sign-in and look similar on the surface, so an organization created in one is easy to mistake for the other — especially if you used Zoho Books at a previous job and that organization is still attached to your email.
Check the app name and logo at the top left. If it says Books and you want Invoice, go to https://invoice.zoho.com/ and sign in with the same credentials. The two are separate organizations, and both can live under one login.
My verification code or OTP never arrives. Codes fail to arrive for boring reasons far more often than technical ones.
If nothing lands after two attempts, contact support@zohoinvoice.com rather than creating a second account. A duplicate account is how the "missing data" problem above starts.
I no longer have access to the email address I signed up with. This one needs support, and it needs proof, which is the point, since it is the same barrier that stops anyone else from claiming your account.
Write to support@zohoinvoice.com with your organization name, the old email address, the new one you want, and any detail that ties you to the account, such as recent invoice numbers. Do it before you leave the old workplace or close the old mailbox if you possibly can.
Can I run two businesses from one login? Yes. One login can hold multiple organizations, and each one keeps its own customers, invoices, numbering, currency and tax setup. Nothing crosses over.
Click on the Organization Name dropdown at the top right.
Choose Manage> + New Organization.
Enter the organization name, country and currency.
Two things worth knowing before you create: transaction limits apply per organization, and moving records between two organizations later is a manual export and import rather than a switch. If the two businesses genuinely share nothing, separate organizations are right. If they are the same business with two names, one organization is simpler.

The short version
Data missing → check which email you signed in with, then check the organization switcher.
Familiar-but-wrong screen → you are probably in Zoho Books or Zoho Billing, not Zoho Invoice.
No OTP → check your spam folder, wait for sixty seconds, verify the number on record, then contact support.
Lost signup email → only support can move it, and they will ask you to prove ownership.
Two businesses → two organizations under one login, separate limits.
How many organizations do you have under your login? Has anyone else discovered a second one they’d completely forgotten about?