Starter plan — up to 50 companies · Monthly

Start your 30-day free trial

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30-day free trial Cancel anytime Secure checkout via Stripe

We only read public Companies House data — we never see your clients' accounts, tax records, or anything sensitive.

We'll send filing alerts here. Privacy Policy.

As a customer you'll also get occasional product tips and updates (one-click unsubscribe in every email).

By continuing you agree to our Terms of Service and Privacy Notice.

What happens next
1. Enter your card details — no charge for 30 days. Cancel any time before your trial ends.
2. Add your clients' company numbers — takes about 2 minutes. We accept CSV exports from major practice management tools.
3. PenaltyProof checks every morning — you'll get an alert for any upcoming deadline from tomorrow. Deadlines pulled daily from Companies House.

Example alert email

Example PenaltyProof filing deadline alert email

Open full sample alert

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EARLY ACCESS

Reviews as they come in.

PenaltyProof is new. We are in early access and collecting feedback from the first practices through the door. When customers share quotes, we will publish them here verbatim — no star inflation, no summary counts.

Using PenaltyProof? We want to hear from you.

Email hello@penaltyproof.co.uk with your experience. What was the first deadline you caught? What would you tell another accountant?