Tanvir Alam•Sep 14, 2026•6 min read•Tax & Compliance
Most rejected VAT reclaims trace back to a small, repeatable set of receipt errors, from missing VAT numbers to claiming on non-VAT-registered suppliers, all of which are easy to catch before submission.
Ask any bookkeeper who has processed VAT returns for more than a year, and they will describe roughly the same list of errors, showing up in roughly the same order, client after client. VAT reclaim mistakes are rarely exotic. They are small, repeatable receipt problems that slip through because nobody looked closely enough before the return went in.
Catching these before submission takes minutes per client, and it is worth folding into a broader year-end receipt checklist rather than treated as a VAT-quarter-only exercise. Catching them after HMRC raises a query takes considerably longer, and the client is the one who ends up with a VAT bill they thought was already settled.
The rule: no supplier VAT number on the document means no valid VAT invoice, and no reclaim.
A valid VAT invoice must show the supplier's VAT registration number, along with the other details HMRC sets out for VAT invoices. Till receipts, especially from smaller suppliers, sometimes omit it, particularly on handwritten or informal receipts from tradespeople and small retailers. Without it, HMRC can and does reject the input VAT claim outright, regardless of whether VAT was clearly charged on the purchase.
This is worth flagging to clients directly: if a receipt does not show a VAT number, ask the supplier for a proper VAT invoice before submitting the expense, rather than assuming the reclaim will go through unchallenged.
The rule: if the supplier is not VAT registered, there is no VAT in the price to reclaim, whatever the receipt total looks like.
Not every supplier charges VAT, and not every amount that looks like VAT on an invoice actually is. Small suppliers below the VAT registration threshold cannot charge VAT at all, and any figure on their invoice that resembles a VAT line is not reclaimable. This error shows up most often with sole trader suppliers and very small local businesses, where the invoice format looks similar to a VAT-registered one but the VAT number field is simply blank or missing.
The rule: where an expense has both business and private use, only the business proportion is reclaimable, and the apportionment needs to be evidenced.
Expenses with both business and private use, most commonly mobile phone contracts, vehicle costs, and home office equipment, require an apportionment between business and private use. Claiming the full VAT amount on a mixed-use expense is one of the most consistent errors HMRC flags during compliance checks, because the apportionment rule is well established but easy to overlook when a receipt simply shows one total figure.
The rule: VAT on business entertainment is blocked. Staff entertainment is treated differently and can be reclaimable.
VAT on client entertainment is almost never reclaimable, a rule that catches out practices dealing with hospitality-heavy clients in particular. Staff entertainment has different, more permissive rules, which creates confusion when a single receipt covers both a staff meal and a client meal on the same bill. The safest approach is to require clients to separate staff and client entertainment onto different receipts wherever possible, rather than reconstructing the split after the fact.
The rule: input VAT must be reclaimed within four years. After that the entitlement is lost, however well documented the expense is.
Input VAT can generally be reclaimed within four years of the invoice date, but receipts sometimes surface well after that window has closed, particularly from clients who have just switched from another accountant or who kept a shoebox of unprocessed paperwork for years before engaging a practice properly. A receipt found and processed after the time limit has passed simply cannot be reclaimed, no matter how valid it otherwise is, which is one more reason the HMRC retention rules for receipts are worth building into a client's routine rather than leaving to chance.
The rule: one purchase, one reclaim. Duplicates usually arrive as a photo and a forwarded email of the same receipt, not as deliberate double-claiming.
Duplicate claims happen more often than most practices assume, usually because the same receipt was submitted twice through different channels: once as a photo from the client's phone, once as a forwarded email attachment from a supplier. Without a consistent capture process, the kind covered in how to scan receipts for business expenses properly, this error is genuinely difficult to catch through manual review alone, especially at volume.
The rule: if the document cannot be read, it cannot support a claim. A faded thermal receipt is a lost reclaim unless a legible copy was captured in time.
Faded thermal paper, receipts left in a pocket through the wash, or handwritten amounts that are simply hard to read all create the same problem: an amount gets estimated or approximated rather than read directly off the receipt. If HMRC ever queries that specific claim, an illegible receipt with an estimated figure offers no real defence, and the VAT reclaim is at risk regardless of how reasonable the estimate was, exactly the habit our guide to keeping business receipts as a sole trader is meant to head off.
Most of these seven errors share a common root cause: someone had to read a receipt manually, under time pressure, and either missed a detail or made a judgement call that later turned out to be wrong, a problem that has shifted rather than disappeared over the last decade of receipt scanning technology. Automated extraction does not eliminate every VAT judgement call, particularly around mixed-use apportionment and entertainment rules, which still need a human decision. But it does remove the errors that come from simple oversight: a missing VAT number that should have triggered a flag, a duplicate submission that went unnoticed, or a faded amount that was never actually confirmed against a clear figure.
Receiptflow's duplicate detection catches the sixth error on this list automatically, flagging repeat submissions before they reach the ledger. Its automated extraction also surfaces missing VAT numbers and unclear figures at the point of capture, rather than three months later when the VAT return has already been filed. For a practice processing VAT reclaims across dozens of clients every quarter, catching these errors at the point of entry, rather than during a stressful pre-submission review, is where the real time saving happens.
See Receiptflow's extraction and duplicate detection in action with a free trial.
No, a valid VAT invoice must show the supplier's VAT registration number, and HMRC can reject the input VAT claim if it is missing.
Input VAT can generally be reclaimed within four years of the invoice date, after which historical receipts can no longer be used to support a claim.
VAT on client entertainment is almost never reclaimable, while staff entertainment follows different, more permissive rules, so the two need to be recorded separately.
A duplicate submission risks a duplicate VAT reclaim, which is a compliance error if not caught before the return is filed, and automated duplicate detection is the most reliable way to catch it at volume.
No. If the supplier is not VAT registered, there is no VAT in the price to reclaim regardless of what the invoice total looks like, and any figure resembling a VAT line on their paperwork is not reclaimable.
How long sole traders must keep receipts, what HMRC actually accepts as valid evidence, and what happens if a receipt goes missing before the five-year retention window is up.
HMRC receipt retention rules differ by entity type. Here is exactly how long sole traders, limited companies, and VAT-registered clients must keep records, and the date the clock starts.
No. Mixed-use expenses such as mobile phone contracts, vehicle costs, and home office equipment require an apportionment between business and private use, and only the business proportion is reclaimable, with the apportionment evidenced.
An illegible receipt with an estimated figure offers no real defence if HMRC queries the claim, so the reclaim is at risk regardless of how reasonable the estimate was; capture a legible copy as early as possible rather than relying on a faded original.