If your practice uses Zoho Sign, you can send a client's statutory accounts, Corporation Tax computation and CT600, or their SA100 Self Assessment return, for e-signature straight from Tax Optimiser. Zoho emails your client a signing link. When they sign, Tax Optimiser saves the signed PDF and Zoho's completion certificate against the review and fills in the approval date for you. Your client doesn't need a Tax Optimiser login. This guide covers connecting your Zoho Sign account and sending your first document.
Before you start
- A Zoho Sign plan with API access. That means Zoho Sign Enterprise, or the Zoho Sign API plan with credits. Each document sent through the API uses Zoho Sign credits (currently 5 per envelope). Credits are bought from Zoho, not from Tax Optimiser.
- A Zoho Sign administrator login. You need one to connect the account and to set up the webhook.
- Client review switched on for your firm: Firm Settings → Firm, tick Send Accounts and Corporation Tax to Clients for Review and Approval.
Step 1 — Connect Zoho Sign
Open Firm Settings → Firm and choose the Integrations tab. Under Zoho Sign, click Connect Zoho Sign. You're taken to Zoho to sign in. Use your Zoho Sign administrator login, then click Accept to let Tax Optimiser create and read signature requests on your behalf. Zoho works out which region your account is in (UK, EU, US and so on) automatically.
You're brought back to the Integrations tab, which now shows Connected account with your Zoho email and region.
Step 2 — Set up the webhook (recommended)
A webhook lets Zoho tell Tax Optimiser the moment a client opens, signs or declines. Without one, Tax Optimiser checks Zoho every 15 minutes instead, so it still works, just more slowly.
- On the Integrations tab, click Create secret. A webhook secret appears. Copy it now: it is only shown once.
- Copy the Webhook URL as well.
- In Zoho Sign, go to Settings → Developer settings → Webhooks and click Create webhook.
- Give it a name (for example Tax Optimiser) and paste the Webhook URL as the callback URL.
- Tick these events: Sent, Viewed, Signed by a recipient, Completed by all, Declined, Recalled and Expires.
- Turn on HMAC signature, paste the webhook secret, and save.
If you ever lose the secret, click Create a new secret and paste the new one into the same webhook in Zoho Sign.
Step 3 — Try it in test mode (optional)
Tick Test mode on the Integrations tab to send documents in Zoho's test mode. They're watermarked and use no credits, and Zoho allows up to 50 a month. Send one to yourself to see what your clients will receive, then untick it before sending real documents.
Step 4 — Send accounts and Corporation Tax for signature
Open the client's accounting period and find the Client review panel. Click Send for review and choose E-signature with Zoho Sign.
- Pick the director who is signing. Their name fills in. Enter their email address.
- Choose the documents: Statutory accounts, Corporation Tax computation and CT600, or both.
- Click Send.
Tax Optimiser combines the documents into one PDF. It adds a final Approval and signature page carrying the approval statement for the accounts and the HMRC declaration for the CT600, with a signature box and date. Zoho then emails the director. Zoho sends reminders every 5 days, and the request expires after 30 days.
To have more than one director sign, send a separate request to each.
Step 5 — Send an SA100 for signature
On the client's Self Assessment return, find the Client review card, click Send for review, choose E-signature with Zoho Sign, check the name and email, and click Send. The sign-off page carries the SA100 declaration.
Step 6 — Follow it and get the signed copy
The request appears in the Client review panel with its status: Out for signature, Opened, Signed, Declined or Expired.
- Remind asks Zoho to email the client again. The refresh button checks Zoho straight away.
- When the client signs, the request shows Signed, with links to the Signed copy and the Completion certificate. For accounts, the director signage date is filled in with the date they signed. For a Corporation Tax-only request, the CT600 declaration date is filled in instead. A date you have already entered is never changed, and a locked (filed) period is left alone.
- If the client declines, their reason appears under the request. Fix what they raised and send again.
- Withdraw recalls the request in Zoho, so the signing link stops working. Sending a new request to the same person replaces and recalls the old one.
Disconnecting
Click Disconnect on the Integrations tab. Requests already out for signature stay in Zoho, but their status stops updating in Tax Optimiser. If Zoho ever disconnects on its own, Integrations shows Reconnect Zoho Sign. This happens when the access is removed in Zoho, or when the Zoho password or two-factor settings change. Click it to connect again.
Troubleshooting
- "Your Zoho Sign account has run out of credits": buy more credits in Zoho Sign, then send again.
- Statuses update slowly: set up the webhook (Step 2), or click the refresh button on the request.
- The webhook isn't working: check that the secret in Zoho matches. If unsure, create a new secret and paste it into Zoho again.
- Need another integration? Contact support from the Integrations tab and tell us which one.
