file CT600 and Companies House micro accounts

First, check whether Corporation Tax is already enrolled on your Government Gateway — log in at gov.uk/log-in-register-hmrc-online-services and look for "Corporation Tax" in your list of services. If it shows as active, you don't need the activation code and can go ahead and submit through TinyTax right away.

If Corporation Tax isn't listed yet, given your 30 April deadline the quickest option is to call the HMRC Corporation Tax helpline on 0300 200 3410 and ask them to resend the activation code or confirm your enrolment status. They can often sort this over the phone, which is much faster than waiting for another letter.

A few more things worth knowing:

- The activation code is posted to your company's registered address at Companies House — make sure that's where you've been checking
- Once you enter the code on the Gateway, wait 30–60 minutes before trying to submit in TinyTax, as HMRC's systems can take a little while to update

If your ex-accountant is an HMRC-authorised agent with Corporation Tax on their Gateway, they can file on your behalf through TinyTax using the "Tax agent" option at the submission step — worth a quick message even if they're busy for a couple of days.

If you do miss the 30 April deadline because HMRC's code hasn't arrived in time, you can appeal any late filing penalty explaining the circumstances — HMRC does consider delays caused by their own systems.

HMRC can definitely help with this over the phone — the CT helpline is set up specifically for situations like yours.

Call 0300 200 3410 (HMRC Corporation Tax helpline, open Monday to Friday 8am–6pm) and ask them to re-send your Corporation Tax activation code. In many cases they can activate the service on your account while you're on the call, so you might not even need to wait for a letter.

Have these to hand when you call:
- Your Company UTR (10-digit number from HMRC's letters — it'll say "Unique Taxpayer Reference")
- Your company registration number
- The registered address for your company at Companies House (that's where any re-sent letter would go)

Given your 30 April deadline, calling first thing tomorrow morning is your best option.

One more thing: if your ex-accountant has Corporation Tax registered on their own Government Gateway with HMRC agent authorisation, they could still file on your behalf through TinyTax — it only takes a couple of minutes at the submission step. Might be worth a quick message to them even if they're otherwise busy.

No need to wait until tomorrow — the HMRC Corporation Tax helpline (0300 200 3410) is open Monday to Friday, 8am to 6pm, so you can call again today or at any point before your 30 April deadline.

Getting through does depend on how busy they are. Calling right at 8am when they open tends to have the shortest waits — mid-morning and after lunch are typically busiest.

If you call back and still have trouble: try ringing a couple of times, as call volumes vary minute to minute, and a disconnect doesn't mean the line is closed.

If the 30 April deadline passes and you're still unable to file because the activation code hasn't arrived and you couldn't get through, you can appeal any late filing penalty explaining those circumstances. HMRC does take delays caused by their own postal or phone systems into account when reviewing penalty appeals.

Yes, you can file your Companies House accounts now and come back for the CT600 once your activation code arrives.

Your current filing session is already set up for both. Here is what to do:

1. Continue the filing — work through the form and enter your figures as normal
2. When you reach the Review & Submit page, you will see two separate submission steps
3. Submit your Companies House accounts first — this only needs your Companies House authentication code (the 6-character code, not the HMRC CT activation code you are waiting for)
4. Your CT600 will remain ready but not submitted
5. Once your Corporation Tax activation code arrives by post, enter it on the HMRC Government Gateway to complete CT enrolment, then log back in and submit the CT600 from the same filing session

The Companies House and HMRC obligations are submitted separately, so filing accounts today meets the CH deadline independently.

If you run into any trouble finding the Review and Submit page, just reply here and we will help you navigate to it.