Keep your R&D claims on track
Knowing when to file your R&D tax claim can be confusing. This tool works it out for you in seconds, so you always know exactly what’s due and when.
If you’re claiming R&D tax relief, there are several deadlines that determine whether you can make a claim. Missing one could mean losing out on relief your business may be entitled to.
If your company hasn't made an R&D claim recently, you must alert HMRC of your intention to claim within six months of your accounting period end date — before any figures are submitted.
Note: this pre-notification requirement doesn't apply in every situation and depends on your company's prior claim history with HMRC.
Statutory accounts must be filed at Companies House within nine months of your accounting period end. HMRC cross-references these figures when processing your R&D claim, so late or inaccurate accounts can delay or jeopardise your relief.
Your corporation tax return is due within 12 months of your accounting period end. Your R&D tax credit claim is embedded within this return, making accurate and timely filing essential to securing your relief.
R&D claims can be submitted or amended for up to two years following your accounting period end — even if the original CT600 has already been filed. Once this window closes, HMRC will not accept any further submissions or amendments for that period.
This is the absolute cut-off for amending your corporation tax return to add, update, or correct an R&D claim. After this date, no further changes can be made to that accounting period.
Need clarity on your R&D claim deadlines?
If you are unsure which deadlines apply, or want a second view on your position, we can help you work through it clearly.