Property auction due diligence is not one thing. What you check on a freehold house is genuinely different from what you check on a leasehold flat — and the leasehold version is significantly more involved, because the costs can be buried in layers that a quick read will not surface.

This checklist covers both. But before any of it: there is one step most people skip entirely, and it costs them hours.

Before You Open a Single PDF: Phone the Auction House

I mean it. Before you start reading the pack, before you run it through any tool, before you spend your evening on due diligence — phone the auction house and have a conversation about the property.

Auction catalogues are not always up to date. Properties get withdrawn, sell prior, or have circumstances that change after the catalogue goes live. I have wasted real time doing thorough due diligence on a property that had already sold because nobody had updated the listing.

But beyond the basic status check, the conversation is genuinely useful. Auctioneers know things that are not in the pack — why the seller is selling, whether there have been previous failed sales, what the reserve is likely to be in the region of. They will not always share everything, but they will share more than you expect if you ask the right questions.

Write down what they tell you. When you upload the pack to AuctionPackReader, paste that context in. The tool works better when it knows what to look for.

Step 1: Check the Pack Is Complete

Before you read anything, check what is actually there. Every pack should contain as a minimum: title register and title plan, Special Conditions of Sale, General Conditions of Sale, local authority search, water and drainage search, environmental search, EPC, Property Information Form (TA6), and Fixtures and Fittings Form (TA10).

If any are missing, note it. If searches are missing entirely, you are either commissioning your own or bidding without them.

Step 2: Title Register and Plan

Check the seller matches the registered owner. Look for charges that need discharging, restrictive covenants, rights of way, flying freeholds, and anything unusual about the boundary on the plan versus what you saw on the viewing.

Confirm access to all parts of the property. Check for any pending applications or disputes noted in the register.

Step 3: Special Conditions of Sale — Read Every Line

This is where costs hide. Look specifically for: buyer pays seller's legal fees, buyer pays auctioneer's commission, search fees charged to buyer, non-standard completion period, service charge arrears transferred to buyer, ground rent arrears transferred to buyer, and any indemnity obligations. Add up every cost you find before you decide what to bid.

Step 4: Freehold Specific Checks

For freehold properties, the main additional checks are planning history (have any extensions or conversions been done with the right permissions?), building regulations completion certificates for significant works, Article 4 directions if you are buying for HMO use, Japanese Knotweed disclosure and management plan, spray foam insulation (common in older stock — lenders dislike it significantly), and tenancy details if the property is occupied.

Step 5: Leasehold Specific Checks

Leasehold due diligence is a different level of work. Start with the lease term — under 80 years is a caution, under 70 is a serious financing problem. Then: ground rent and whether it escalates, ground rent arrears, service charge level and arrears, service charge accounts for the last 3 years, reserve or sinking fund balance, any Section 20 major works consultations, restrictions on subletting or alterations, and management company details.

The cost risk with leasehold is not just what is in the pack today — it is what is coming. A building with ageing communal systems and no reserve fund is a building where a large unexpected bill is a matter of when, not if.

Step 6: Costs You Would Inherit on Completion

This is the check that catches people most often. Service charge arrears, ground rent arrears, unpaid utility bills on vacant properties, a non-paying tenant (check the rent account, not just the tenancy agreement), an unprotected tenant deposit, outstanding works orders or enforcement notices, and any indemnity insurance obligations in the Special Conditions.

Step 7: Use the Triage Tool, Then Use the Solicitor

My process: phone call first to get context, pack into AuctionPackReader with that context included, then the checklist against what comes back. If the deal still looks good, the pack goes to a solicitor with a specific brief — not a cold instruction, but a focused one based on what the triage flagged.

This is not a shortcut to skipping legal advice before you bid. It is how you make sure you only spend money on deals worth pursuing.

For a deeper look at what the most common dealbreakers look like in practice, 7 red flags in auction legal packs goes through each one. For the costs involved in getting proper legal advice, auction legal pack solicitor cost has the honest breakdown. And if you want to understand the actual reading process, how to read an auction legal pack takes you through it step by step.

If all of this feels like a lot to hold in your head — it is. Due diligence is learnable, but it takes time, repetition, and ideally other people who have already made the mistakes to learn from. The Property Wealth Systems network is where I would point anyone who wants a proper grounding in property investment with a community around them. Full disclosure: I earn a small commission if you join through my link — but I know these people personally and I would not send you somewhere I did not trust.