The short version
Rent arrears are arithmetic, not a feeling. What was due, minus what was received, oldest period first. Every argument an agent has about arrears — with a tenant, with a landlord, in a courtroom — goes better when that number is derived from records rather than remembered.
Since 1 May 2026 the legal picture has narrowed. Section 21 is gone, so possession runs through a Section 8 ground, and the arrears grounds have their own thresholds: Ground 8 needs three months' arrears and is mandatory, Grounds 10 and 11 are discretionary. All three carry four weeks' notice.
But the part that decides whether you ever get near a notice is the first fortnight, and it is almost entirely operational. This guide covers both: the chase sequence that clears most arrears before they become a legal question, and the law for the ones that do not.
When rent is actually late
Rent due on the 1st is not late on the 1st. It is late on the 2nd.
That is not pedantry. The moment you write to a tenant saying they are "five days late" when they are four, you have handed them a correction to make instead of a payment, and you have put your own record-keeping in question. The same applies to the figure: quote the arrears wrong once and every subsequent number you send is negotiable.
Three frequencies, three ways of counting:
| Frequency | Due date | Late from |
|---|---|---|
| Monthly | The due day each month, clamped to the month's end where the day does not exist | The day after |
| Weekly | Every 7 days from the tenancy's anchor date | The day after |
| Four-weekly | Every 28 days from the tenancy's anchor date | The day after |
A monthly tenancy with a due day of the 31st is due on 28 or 29 February. Getting that clamp wrong is one of the more common sources of a wrong arrears figure, because the error compounds quietly across a year.
The first fortnight is not a legal problem
Most missed payments are not defaults. They are a changed bank account, a standing order that lapsed after a bank migration, a payday that moved, a tenant who has gone on holiday and mis-timed it. In a healthy portfolio the large majority of missed payments clear within a fortnight, and almost all of those clear because somebody sent a short, friendly message the morning after.
A sequence that works:
- Day 1 (the morning after). A short message. Rent was due yesterday, we have not seen it, here are the payment details, let us know if something has changed. No mention of consequences. The goal is to make paying easy, not to establish a record.
- Day 3 to 5. A phone call if nothing has landed. This is where you find out whether it is an admin problem or a money problem, and those two need completely different handling from here on.
- Day 14. The tone changes. A written statement of the account — what was due, what was received, what is outstanding — and a request for a payment plan if the tenant cannot clear it. This is the first document you would be comfortable showing a judge.
- Day 14 onwards, every fortnight. A regular, unemotional cadence. Not daily contact, which reads as harassment and produces nothing; not silence, which lets three months accumulate while everyone hopes.
The threshold worth naming inside your own agency is fourteen days. Before it, you are doing customer service. After it, you are managing a debt, and the landlord needs to know about it. Agents who blur those two either panic on day two or discover a problem in month four.
The arrears grounds since Section 21 went
With no-fault possession abolished, every claim is evidenced. For rent arrears there are three grounds, and choosing between them is a real decision rather than a formality.
| Ground | What it covers | Type | Notice |
|---|---|---|---|
| 8 | Serious rent arrears — at least 3 months (13 weeks if rent is weekly or fortnightly) | Mandatory | 4 weeks |
| 10 | Any rent arrears outstanding when the notice is served | Discretionary | 4 weeks |
| 11 | Persistent late payment, even if the account is clear today | Discretionary | 4 weeks |
Ground 8 is the strong one and the fragile one at the same time. Mandatory means that if the ground is made out, the court must order possession. But the three-month threshold has to be satisfied twice — on the day the notice is served and again on the day of the hearing. A tenant who pays enough to drop below the threshold the day before the hearing defeats it. That is not a loophole so much as the design: the ground exists for arrears that are genuinely entrenched.
Ground 11 is the one agents forget. It covers the tenant who always pays, but always three weeks late, and whose account happens to be square on the day you look. There is nothing to recover, so nothing focuses the mind, and the pattern runs for years. It is discretionary, so the judge weighs whether possession is reasonable — which means your evidence is a payment history, not a balance.
Because notice periods and grounds interact, and because citing several grounds means the longest period wins, the arithmetic is worth doing carefully rather than in your head. Our Section 8 notice period calculator does the date part; which ground genuinely applies is a legal judgement and remains yours. The wider picture — every ground, not just the arrears ones — is in Section 8 grounds for possession.
Check your own file before you serve anything
Arrears claims rarely fail on the arrears. They fail on the landlord's paperwork, and they fail late, after costs have been incurred.
Before a notice goes out, confirm every one of these:
- The deposit was protected in time and the prescribed information served. The 30-day clock and what counts as service are covered in deposit protection deadlines.
- A current gas safety record was given to the tenant, and one was given before they moved in.
- The EPC and the How to Rent guide were served at the start of the tenancy.
- Any licence the property needs is in place — mandatory HMO, additional, or selective. An unlicensed property is a problem well beyond the possession claim.
- The rent you are claiming is the rent lawfully in force. If it was increased, it was increased by a valid Section 13 notice with two months' notice and no more than once in twelve months. An increase served wrongly means part of your arrears figure is not owed.
None of these are exotic. All of them are things an agency with a proper compliance register can answer in seconds and an agency without one answers by searching an inbox.
Record the account, not the story
The evidence that wins an arrears case is dull: a schedule showing each period, the rent due for that period at the rate then in force, the payments received and when, and the running balance. Not a narrative of phone calls.
Two details that trip people up:
Rent rises must not rewrite history. If the rent went from 1,150 to 1,250 in April, the periods before April are owed at 1,150. A system that stores only the current rent and multiplies it by the number of periods will overstate the arrears — and an overstated figure, once spotted, undermines everything else you have said.
A new tenancy is a clean slate. Arrears belong to the tenant who incurred them. When a tenancy ends and a new one begins, the balance does not carry across to the incoming tenant, and a backdated tenancy start should not conjure debt for periods before anyone was recording anything.
Where a system earns its place
Everything above can be done in a spreadsheet, and plenty of agencies do. What a spreadsheet cannot do is notice. It will not tell you on the morning of the 2nd that four properties did not pay, and it will not tell you on day fourteen that one of them has crossed from admin problem to arrears.
That is the job Proplio does on the rent side: rent and due day on the property, payments recorded in a tap or matched automatically from an uploaded bank statement, and the position derived — paid up, late, or in arrears — rather than stored. The morning after a payment is missed, the agency gets one email. At fourteen days, another, and every fortnight after that. Tenants can get a courtesy reminder three days before rent is due, which is the cheapest arrears prevention there is. And because the same system holds the certificates, the file you need before serving a notice is already assembled. Flat 29 pounds a month, unlimited properties, unlimited team — start a free trial if you want to see it against your own portfolio.
Key takeaways
- Rent is late the day after it was due, and the arrears figure is arithmetic — due minus received, oldest period first, at the rate in force for each period.
- The first fortnight is customer service; after fourteen days you are managing a debt and the landlord needs to know.
- Since Section 21 went, arrears run through Ground 8 (3 months, mandatory, 4 weeks' notice), Ground 10 (any arrears, discretionary) and Ground 11 (persistent lateness, discretionary).
- Ground 8's threshold must be met twice — at service and at the hearing — so a part-payment before the hearing defeats it.
- Claims fail on the landlord's paperwork, not the arrears: deposit, prescribed information, gas record, EPC, How to Rent, licensing, and a validly served rent increase.
- Rent rises must not rewrite history, and arrears do not follow the property to the next tenant.
This article is general guidance for letting agents in England as of August 2026 and is not legal advice. Possession grounds, notice periods and their thresholds have exceptions and change over time; confirm the current position with the legislation or a qualified adviser before serving anything. Proplio is our product.