Getting ECO4 Flex funding isn't complicated. But miss one document? Your application dies before it starts.
The ECO4 LA Flex scheme opens doors for households that don't qualify for standard ECO4. You get free energy upgrades through flexible routes if you bring the right paperwork. Each route has specific requirements. Know yours before you apply.
Universal Documents (Everyone Needs These)
Think of these as your entry ticket. No exceptions, no shortcuts.
Proof of Identity
Accepted documents:
- Valid passport
- UK driving licence
- National ID card
Clear photocopies or digital images work fine. Blurry photos? Application rejected.
Proof of Residence
You need recent proof that you live where you claim. Within 12 months, showing your name and full address.
Old documents get rejected. Check the date before
submitting.
Proof of Property Rights
Homeowners: mortgage statement (last 12 months), property deed, or Land Registry entry. Tenants: signed tenancy agreement and obtained written landlord consent. No landlord permission letter? Application denied. Doesn't matter how perfect your other documents are.
The consent letter needs the landlord's approval for the specific energy work. Simple letterhead confirmation works.
Route 1: Low-Income Eligibility
Does your household earn under £31,000 annually? This route's built for you. But here's the catch: self-declarations mean nothing. You need hard evidence covering all household incomes.
What Counts as Income Proof?
Employed workers:
- Previous year's P60 (if issued within 6 months)
- Tax return documentation
- Three months of recent payslips
Multiple jobs? Provide P60S from each employer.
Pensioners:
- Annual pension statement
- Three consecutive months of pension payments
Self-employed:
- Three months of recent payslips
- Three months of bank statements (all income accounts)
Recently changed jobs? Your P45 helps, but it can't stand alone.
Proving Household Numbers
Why does this matter? Because the £31,000 threshold applies to your entire household, not just you.
Acceptable evidence:
- Council tax letters
- Tenancy agreements
- Mortgage statements
- Electoral register entries
- Bank statements showing multiple household deposits
No guessing. Councils verify everything.
Route 2: Proxy Targeting (The Vulnerability Route)
Don't claim benefits, but facing hardship? Route 2 recognises genuine struggle through vulnerability indicators.
You need exactly two qualifying proxies. Not one. Not three. Two.
The Six Proxies (Choose Your Two Carefully)
- Proxy 1: LSOA Targeting
Live in a deprived area? Get a screenshot from your local authority confirming your property sits in LSOA 1-3. Cross-reference it with ONS Postcode Directory data.
Cannot combine with Proxy 3.
- Proxy 2: Council Tax Reduction
Receiving council tax reduction (not single-person discount)? Provide your council tax bill showing the reduction, or get a formal letter from the authority.
This proves financial strain without revealing full income.
- Proxy 3: Medical Vulnerability
Cold homes worsen your health condition? You need:
- Signed GP referral letter (NHS headed paper, official stamp, NHS email validation)
- Or the NHS Summary Care Record showing medication for NICE Guidance conditions.
- Pregnant? MAT B1 form showing due date works.
- Cannot combine with Proxy 1.
- Proxy 4: Free School Meals
Get free school meals due to low income? Provide Eligibility Checking Service (ECS) documentation from the Department for Education or your child's school.
Direct proof that the authority recognises your vulnerability.
- Proxy 5: Local Authority Support Scheme
Your council runs a dedicated low-income scheme and nominated you? They'll provide a signed letter confirming your participation.
- Proxy 6: Energy Bill Support Referral
Energy supplier or Citizens Advice for bill struggles? Gather:
- Signed referral letter
- Proof of debt (arrears statements or disconnection notices)
- Cannot combine with Proxy 7.
Proxy Pairing Rules
Pick your strongest two. Gather documents. Submit.
Route 3: NHS Referrals
Severe health condition made worse by cold homes? Income doesn't matter here. Medical need qualifies you.
The Critical NHS Referral Letter
Your GP, NHS Foundation Trust, or NHS Trust healthcare professional must provide:
- Signed letter on official NHS headed paper
- Doctor's name, GMC number, practice address
- Official GP surgery stamp
- Sent electronically from a valid NHS email to the local authority
The letter must state that you suffer from one of four conditions:
- Cardiovascular disease (heart disease, hypertension, stroke)
- Respiratory disease (asthma, COPD, cystic fibrosis)
- Limited mobility conditions
- Immunosuppression disorders
Vague language weakens applications. Diagnostic terms matter.
Supporting Documents for Route 3
Beyond the referral, you still need:
- Proof of identification
- Proof of residence
- Property ownership/tenancy evidence
An Energy Performance Certificate (EPC) helps, though surveyors can create one if needed.
Important: GP referrals are free. No charges allowed. Some GPs don't know ECO4 Flex—give them Ofgem's referral template.
Route 4: Bespoke Targeting
BEIS-approved schemes only. Requirements are assessed case-by-case.
Contact your local authority to confirm if this route exists in your area. Don't assume it does.
Property Requirements
Every route requires an Energy Performance Certificate (EPC) showing an E to G rating. EPCs last ten years.
Check if yours exists at the UK Government's Find an Energy Certificate webpage. No EPC? Your approved installer arranges a free survey and certificate.
Document Timing and Format
Age matters. Most evidence must be dated within 12 months of your application signature.
12-month rule applies to:
- Utility bills
- Council tax statements
- Payslips
- Pension statements
- Bank statements
- Benefit letters
Older documents can support recent ones, but primary evidence stays current.
Format flexibility:
Photocopies, clear digital photos, and PDF scans, all acceptable. But keep originals for three years. Ofgem audits happen. Blurry or cut-off documents? Automatic rejection.
Application Strategy
Don't apply directly to councils. They reject direct applications. Apply through approved ECO4 Flex installers or agents listed by your council. They handle document collection, verification, and submission.
Before You Submit
Create a checklist for your route. Tick off each item. Missing one document delays you weeks or months.
Request your local authority's Statement of Intent early. It shows which routes your council accepts and any area-specific requirements.
Documents unavailable? Contact your council's ECO4 Flex team. Many councils accept alternative evidence proving the same point.
Final Verification Checklist
- All documents are originals or clear, legible copies
- Documents dated within 12 months (where required)
- Full name and address included (where required)
- Documents organised to match your eligibility route
- Landlord consent included separately (tenants only)
The Bottom Line
ECO4 scheme documentation protects scheme integrity. Complete, accurate paperwork prevents rejections and gets you free energy upgrades faster.
Know your route. Gather your documents. Apply through approved installers. Lower heating bills and a warmer home wait on the other side of proper paperwork.
