The Small Business Guide to Auto-Enrolment Pensions

If you employ anyone in the UK—even one person—you have a legal obligation around workplace pensions. Auto-enrolment means you must automatically enrol eligible workers into a pension scheme and contribute toward their retirement. It's not optional, and The Pensions Regulator (the government body that polices this stuff) takes non-compliance seriously. But here's the thing: once it's set up, it mostly runs itself. The key is understanding what you actually have to do, and then doing it.

For most small business owners, auto-enrolment feels like one more compliance checkbox to tick. Alongside corporation tax, payroll, and all the other accounting overhead, it can feel overwhelming. But it's worth spending an hour now to avoid penalties later. Penalties start at £50 per day per worker and escalate from there. So let's walk through it.

What is auto-enrolment?

Auto-enrolment is the UK government's system to make sure more people save for retirement. Your job, as an employer, is to:

Set up a qualifying workplace pension scheme
Automatically enrol eligible workers into it
Contribute at least 3% of qualifying earnings
Manage opt-outs and re-enrol every three years
Keep records for six years (in case The Pensions Regulator comes asking)

The system has been fully in force since 2018, which means it applies to all employers—startups, consultancies, cafés, plumbing firms, everyone. Your size doesn't matter. Your number of employees doesn't matter. Your attitude toward pensions doesn't matter. If you employ someone, you do this.

"Enterprise-grade compliance" usually means "impossible to understand." Auto-enrolment is not. It's actually pretty straightforward once you break it down.

Who must be enrolled and what you must contribute

Eligible jobholders

You must automatically enrol workers who:

Are aged between 22 and State Pension age (currently 66–68 depending on when they were born)
Earn more than £10,000 per year
Work in the UK

Both you and the worker must contribute.

Everyone else

Workers aged 16–21 or over State Pension age can ask to join, and if they do, you must contribute. Workers earning below the lower earnings threshold can also opt in, but you're not legally required to contribute for them—they'd be contributing from their own pocket.

Minimum contribution rates

The math is straightforward. Minimum total contribution is 8% of qualifying earnings:

Who pays	Minimum
You (employer)	3%
Them (employee)	5%
Total	8%

Qualifying earnings are salary between the lower and upper thresholds. These thresholds change annually—check GOV.UK for current figures. You can contribute more if you want—some businesses do to offer a better pension—but you cannot contribute less.

A worked example: An employee earns £25,000 per year. Let's say the lower threshold is £6,240 and the upper threshold is £50,270 (check the current year to be sure).

Qualifying earnings: £25,000 − £6,240 = £18,760
Your contribution (3%): £562.80 per year (roughly £47/month)
Their contribution (5%): £938.00 per year (roughly £78/month)

You can also choose to calculate contributions on total earnings or basic pay instead, as long as the total contributions meet or exceed the 8% threshold on qualifying earnings. Payroll software usually handles this automatically—the trick is just setting it up correctly the first time.

Choosing a pension provider

You need a workplace pension scheme that qualifies under auto-enrolment rules. Your main options:

NEST (National Employment Savings Trust)

NEST is a government-backed scheme designed specifically for auto-enrolment. Any employer can use it, and it must accept you if you apply. Low charges, straightforward setup, employee-friendly. It's the obvious choice for small businesses—especially if you've got no strong reason to choose anything else. Most small firms with 5–15 employees use NEST or something very similar.

Commercial pension providers

Many insurance and investment firms offer workplace pension schemes compatible with auto-enrolment. Charges, investment options, and features vary. Some integrate cleanly with payroll software, others less so. Some offer a wider range of investment funds.

What to compare

Annual management charges — Affects your employees' pension pots over 30 years. A 0.5% difference is huge compound. Don't ignore this.
Default investment fund — Where does employee money go if they don't choose? Is it sensible?
Payroll integration — Does it plug into your current system, or will you be manually uploading data every month? (Hint: you want the former.)
Minimum employer contribution — Most require exactly the legal minimum; some allow you to choose higher.

Pull together quotes from 3–4 providers, compare charges and integration, and pick one before your auto-enrolment duties officially start.

Setting up auto-enrolment

Here's the five-step process:

Step 1: Choose your pension scheme and register

Pick a provider and register with them. You'll get confirmation of your staging date—the day your auto-enrolment duties formally begin.

Step 2: Assess your workforce

Go through your payroll and put each worker into one of three buckets:

Eligible jobholders (must be enrolled)
Non-eligible jobholders (can ask to join)
Entitled workers (can ask to join, but you don't have to contribute)

Reassess whenever someone's age or earnings change significantly.

Step 3: Enrol eligible workers

Write to eligible workers and let them know they've been enrolled. The letter must say:

Which scheme they've been enrolled in
What they and you will contribute
When contributions start
Their right to opt out within one month
Where to find more information

This letter is mandatory—it's part of your legal paperwork trail.

Step 4: Set up your payroll

Configure your payroll software or provider to:

Calculate employee contributions each month
Deduct them from gross pay
Calculate your employer contributions
Track everything separately so you can report it

Contributions go to the pension provider, usually by the 22nd of the month following deduction. Late payments attract penalties. If you haven't yet integrated payroll with your wider business accounting, now is the time.

Step 5: Complete your declaration of compliance

Within five months of your staging date, you must file a declaration with The Pensions Regulator. This is a simple form that says, "I have done all the things I'm supposed to do." You can file it online. Takes about 15 minutes. Do not skip this step.

(If you've got fewer than 50 employees, there's actually a streamlined process—check the Regulator's website for details.)

Ongoing obligations and compliance

After setup, here's what doesn't go away:

Monthly contributions

Every pay period, you calculate, deduct, and pay contributions. This is automated if your payroll software is set up correctly. If you're late, the Regulator notices and issues penalties.

Managing opt-outs

Workers can opt out within one month of enrolment. If they do, refund any contributions already deducted. You cannot encourage them to opt out, and you cannot make it difficult. "You probably don't need this" or "I can save you a few quid" counts as encouragement and is illegal.

Re-enrolment every three years

Every three years, eligible workers who previously opted out are automatically re-enrolled. This gives them another chance to start saving. You must also refile a declaration of compliance. The three-year cycle is easy to miss—set a calendar reminder.

New starters

Every new employee must be assessed and, if eligible, enrolled from their first day (or first pay period, depending on how you've set things up). This is where many small businesses slip up: they onboard someone and forget to enrol them because they're busy. Don't do that.

Record-keeping

Keep documentation of:

Who has been enrolled and when
All contributions paid (your side and theirs)
Opt-out notices
Any communications you've sent to workers about pensions
A copy of your pension scheme details

Hold onto these for six years. The Regulator may ask to see them during an audit. Your records also feed into your wider financial compliance—Making Tax Digital reporting, payroll tax submissions, and end-of-year accounts all benefit from clean pension records.

The accounting side and cash flow

Recording contributions

Employer pension contributions are a business expense. In your accounting software, record them separately from salaries—as a payroll cost, but distinct—so you can see at a glance how much you're spending on retirement benefits. When planning your financial forecasts, factor pension costs into payroll as a fixed line item.

Employee contributions flow through as a reduction in gross pay, then as a liability to the pension provider until you've sent the money.

Cash flow impact

Pension contributions are new outgoings. Don't underestimate this when planning your cash flow. A business with ten employees each earning £25,000 will spend roughly £5,600 per year on employer contributions (3% of qualifying earnings). For twenty employees, it doubles. Build this into your budgets and forecasts.

Integration with payroll

Your payroll provider should handle all the calculation automatically. Confirm they're set up for your chosen contribution basis (qualifying earnings, total earnings, or basic pay) and the right percentage. A mistake here means either short-paying the pension provider (which triggers Regulator penalties) or overpaying (which is your mistake to correct).

Common mistakes to avoid

Missing deadlines

Late enrolment of a worker, late contribution payments to the pension provider, missing your declaration of compliance—all attract penalties. Set reminders at least two weeks before each deadline.

Misclassifying workers

Is this person really ineligible, or did you just forget they turned 22? Spot-check your assessment quarterly. If you miscategorise someone, you have to fix it retroactively and may face a penalty.

Encouraging opt-outs

It is illegal to pressure, bribe, or persuade workers to opt out of auto-enrolment. Even subtly. Even by accident. If someone asks about opting out, point them to the Regulator's website and let them decide. Do not advise them.

Ignoring part-time and casual workers

Auto-enrolment applies to all workers—full-time, part-time, casual, zero-hours contracts. Everyone who meets the age and earnings criteria must be enrolled.

Not re-enrolling

Three years pass quickly. If you miss your re-enrolment date, workers who opted out do not get re-enrolled, and you've breached your obligation. Set a reminder.

Frequently Asked Questions

Can I use a personal pension instead of a workplace scheme?

No. Auto-enrolment requires a workplace pension scheme that's registered with The Pensions Regulator. Personal pensions (including SIPPs) don't count. You need to set up a proper scheme—NEST is the easiest route.

What if someone earns below £10,000 per year?

They're not eligible for auto-enrolment. They can ask to join if they want, and if they do, you must make contributions. But you're not obliged to enrol them.

Can I delay auto-enrolment?

You can postpone it once, for up to three months after your staging date. After that, you must enrol. Postponement buys you time to get payroll software set up, but it doesn't change your obligations—they just start later.

What if I can't afford 3% contributions?

You still have to contribute 3%. That's the legal minimum. If cash flow is tight, it's worth knowing that this is an expense, not a tax—it comes out of profit, not revenue. But you cannot reduce contributions below 3% or postpone them indefinitely.

How do I know if someone is over State Pension age?

Use the State Pension age checker on GOV.UK. Different people have different State Pension ages depending on their birth date. A 65-year-old might be eligible; a 68-year-old might not be. Always check.

What happens if I get it wrong?

The Pensions Regulator will issue warnings and escalating penalties. The first breach might cost you £50–£100 per day per worker. Repeated breaches cost more. Serious failures can lead to enforcement action. In practice, most small businesses that catch and fix their mistakes quickly get away with warnings. But don't test this—get it right the first time.

Does Relentify handle auto-enrolment?

Relentify's accounting platform integrates with payroll so you can track pension contributions alongside salaries, manage records, and see the impact on cash flow and tax planning. Your payroll provider or NEST handles the actual enrolment and contribution payments.

Getting it right, once and for all

Auto-enrolment is mandatory, but it's not complicated. The setup takes a few hours—choose a provider, assess your workers, enrol the eligible ones, configure payroll, file a declaration. After that, it's an ongoing but routine part of payroll.

The penalties for non-compliance are real and escalate quickly. The sooner you get it right, the sooner you can stop worrying about it. Your accountant or payroll provider can walk you through the specifics for your business, and The Pensions Regulator's website has checklists and tools that remove much of the guesswork.

One hour of planning now saves you penalties, admin chaos, and headaches later. Worth the investment.