There is no standard answer, and an adviser who quotes you one is describing their own process rather than your claim. Three things set the calendar: the state of your cost records, the number of projects that have to be described on the Additional Information Form, and how quickly the competent professionals who did the work can give their account of it. What is fixed are the statutory dates around all that — a claim notification window that closes six months after the end of the period of account, and a claim that can be made up to two years after the last day of it. Work back from those, and start earlier than feels necessary.
The three things that consume the time
The state of the records. Where staff time, project boundaries and cost data were captured as the work happened, the finance side of a claim is reconciliation. Where nothing was written down, it is reconstruction. HMRC accepts that R&D costs are often an estimated proportion of known expenditure, provided the estimate is arrived at using evidence and reason — but building an estimate that meets that description takes considerably longer than reading a timesheet. What records you need sets out what to keep, and why keeping it makes the next claim shorter.
The number of projects. The Additional Information Form’s coverage rules mean the writing scales with the count. With one to three projects, all of them are described. With four or more, at least three have to be selected that together account for at least half the qualifying expenditure. Where reaching half would take more than ten, the ten with the highest qualifying expenditure are described. Selecting them still means costing every project claimed, described or not — you cannot identify which projects make up half the qualifying expenditure without pricing all of them.
Access to the competent professionals. The technical account can only come from the people who did the work — HMRC’s own guidance is to get the opinion of a competent professional in the field, often someone already working on the project. The interview hours are modest. Finding them in an engineering director’s diary, twice, is usually the constraint that decides the elapsed time, and it is the one part of the exercise nobody can compress on your behalf.
What adds a step
Some circumstances add work before any number can be written down: a first claim, where the claim notification has to be filed before anything else; contracts to read, where R&D was contracted out or externally provided workers were used; grant funding; a group structure; the intensity computation for Enhanced R&D Intensive Support, which needs relevant costs for connected companies as well as your own; and a PAYE cap exemption, where the reasons for relying on it are disclosed on the form rather than filed away. Each is a question that has to be answered before the arithmetic can start.
The deadlines that actually bind
Two dates decide whether a claim is possible at all, and they are not negotiable.
The claim notification window closes six months after the end of the period of account. It bites on accounting periods beginning on or after 1 April 2023, where you are claiming for the first time or have not claimed in the three years ending with the notification deadline. Miss it and the claim is invalid; there is no late route.
The claim itself can be made, amended or withdrawn for two years from the end of the period of account. The Additional Information Form has to reach HMRC before the Company Tax Return, or on the same day and ahead of it; how to claim R&D tax credits sets out the sequence in full.
Read those together and the planning rule follows. If a notification is needed, the whole exercise sits inside six months of the period end, not two years.
Why we do not quote a turnaround
Because the parts an adviser controls are not the parts that take the time. We can hold our own work to a timetable; we cannot conjure a technical director’s afternoon or invent a cost record nobody made. We would rather agree a realistic timeline at the start of the engagement, say which steps are waiting on whom, and revise it honestly when information is slow.
There is a quality argument underneath the scheduling one. HMRC checked around one in six claims in 2023-24, its latest published figure, so a claim now has to be built to be read by an inspector rather than merely filed. That version takes longer, and it is the only version worth preparing.
Preparation time is not payment time
The two halves of the question are often merged and should not be. Once a valid claim is filed, what happens next is HMRC’s: how long it takes to receive an R&D tax credit covers HMRC’s published aims and what can hold a payment up. Nobody outside HMRC controls that queue, so marketing that promises a payment date is describing work the adviser does not perform.
If a year end is approaching, talk it through with us before the notification window closes rather than after.
Sources
- Tell HMRC that you’re planning to claim R&D tax relief — the claim notification period runs from the first day of the period of account to six months after the end of it, and applies to first-time claimants and to companies whose last claim was made more than three years before the last date of the claim notification period.
- Additional information you must submit before you claim R&D tax relief — the project coverage rules for 1 to 3, 4 to 10 and more than 10 projects; the requirement to submit the form before the CT600, or on the same day and ahead of it.
- CIRD182000: additional information requirement — the AIF asks whether the business is exempt from the PAYE cap and, if so, to explain why.
- FA 1998 Sch 18 para 83E — a claim may be made, amended or withdrawn within two years from the end of the period of account, where that period is not longer than 18 months.
- GfC3: recommended approach to claims and record keeping — get the opinion of a competent professional in the field, often someone already working on the project; claims are more likely to be correct where the company knew at the time that the work might qualify; it is not unusual for R&D costs to be an estimated proportion of known expenditure, and an estimate should be arrived at using evidence and reason and shown to be based on facts; records should be proportionate to the project.
- Check what R&D costs you can claim — the cost categories and the apportionment basis behind the cost work.
- HMRC’s approach to R&D tax reliefs 2023 to 2024 — 9,700 compliance checks against around 61,000 claims received, the source of the one-in-six check rate.
This page describes the rules as they stood at the review date above, as general information rather than advice on your circumstances. For how that distinction works, see our terms; for an answer on your own facts, talk to us.