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A self-build timber-frame house on a rural plot
For Self-Builders & Converters

You can reclaim the VAT on your self-build.
Getting it right is harder than it sounds.

Most self-builds have somewhere between £15,000 and £30,000 of reclaimable VAT sitting in a shoebox of invoices. HMRC's VAT431 scheme only gives you one shot to claim it — miscoded invoices, missed deadlines, or the wrong VAT rate from a contractor can cost you thousands. VATBuild checks every invoice against HMRC Notice 708 as you go, so nothing falls through the cracks before you submit.

How it works

Three steps from invoice pile to HMRC-ready claim

01
431C Conversion

Set up your project

Answer a short set of questions about your build — new build, conversion, or renovation. VATBuild works out which HMRC VAT scheme actually applies to you before you upload a single invoice.

02

Upload your invoices

Add invoices as you go, or all at once at the end. Our AI reads each one, extracts the line items, and checks them against your project's confirmed VAT pathway.

03
Claimable — Notice 708 s12.2
Review — check invoice date

Get a clear verdict

Every line item is marked claimable, review, or not claimable — with a plain-English reason citing the relevant HMRC Notice 708 rule. No guessing, no spreadsheets.

Built on the actual rules

Built around HMRC Notice 708.
Not a generic VAT calculator.

Every classification VATBuild produces is tied back to a specific part of HMRC Notice 708 — the rules that actually govern VAT on building work. That means every "claimable" or "not claimable" verdict comes with a reason you (or your accountant) can check, not a black-box score.

  • Catches contractor invoices charged at the wrong VAT rate, before you pay them
  • Distinguishes 431NB new-build and 431C conversion rules automatically
  • Flags items that need a second look instead of silently guessing
Invoice #INV-2847 — Timber & Roofing LtdLine items

Structural timber frame — supply & fit

Notice 708 §3.2 — zero-rated contractor service

Claimable

Site fencing — hire

Notice 708 §12.2 — confirm date against build period

Review

Fitted carpet — supply & fit

Notice 708 §13.2 — carpets are always blocked

Not claimable

One project. One claim.
No second chances.

Your VAT431 claim happens once, after completion. Start tracking your invoices properly from day one — it's free to set up.