Landlord Property Valuation UK 2026 — RICS Red Book, Down-Valuations & CGT Base Cost

Types of valuation — from AVM to RICS Red Book

• Automated Valuation Models (AVMs): Zoopla Estimate, Rightmove Valuation — algorithm-based, ±10-20% accuracy; not acceptable for HMRC, mortgage, or probate purposes
• Estate agent market appraisal: useful cross-check, not RICS regulated; not acceptable for formal purposes
• Desktop valuation: RICS valuer reviews data without inspecting; acceptable for some standard remortgages but not unusual properties or formal HMRC purposes
• RICS Red Book (full physical): formal written report, physical inspection, RICS registered valuer — required for CGT, IHT, probate, gifting, and down-valuation challenges

When landlords need a formal RICS valuation

• Remortgage: lender instructs their panel valuer — landlord pays but cannot choose the valuer; commission independent Red Book to challenge a down-valuation
• CGT on disposal: RICS valuation needed where base cost is uncertain (inherited/gifted property, connected party acquisition)
• Probate and IHT: property must be valued at open market value at date of death; declare to HMRC; VOA challenges low valuations particularly where property later sells higher
• Gifting to family: HMRC treats disposal at market value (TCGA 1992 s.17) — RICS Red Book valuation at date of gift establishes the market value for donor's CGT and recipient's base cost

Challenging a mortgage down-valuation

• Step 1: request a copy of the valuation report (you are entitled to it as the paying party)
• Step 2: review comparables used — are they genuinely comparable (type, size, condition, location, date)?
• Step 3: gather 3-5 counter-comparables from local agents and Zoopla/Rightmove sold data (last 3-6 months)
• Step 4: submit to the lender's formal review process; lender may instruct a reconsideration or second valuation
• Step 5: if unresolved, commission an independent RICS Red Book valuation and/or approach a different lender