What is the Telephone Preference Service and what does a wash actually do?
The Telephone Preference Service is a UK register that allows consumers, sole traders, and certain partnerships to record their objection to receiving unsolicited live marketing calls. It is administered by the Direct Marketing Association (DMA) under contract from the Government and covers both landlines and mobile numbers. Registration is free to the individual and permanent unless they choose to remove themselves.
A TPS wash takes your telephone list, compares each number against the current register, and either removes matching numbers or flags them so they are excluded from dialling. The register is updated daily, which is why a wash has a short shelf life. A file washed on 1 May is stale by 29 May, even if you have not dialled anyone on it yet.
The practical effect is straightforward: you upload a formatted file of telephone numbers to a wash bureau or directly to the MPS portal, wait for the comparison to run (usually minutes for files under 100,000 records), and receive back either a cleaned file or a suppression flag column. Numbers that hit on the register must not be dialled for unsolicited marketing. Numbers that do not hit are clear to call, subject to the rest of your PECR and UK GDPR obligations.
What is the legal requirement under PECR?
The Privacy and Electronic Communications Regulations 2003 (PECR), specifically Regulation 21, state that a person must not make an unsolicited call for the purpose of direct marketing to a subscriber who has registered with TPS. "Unsolicited" means any call where the subscriber has not specifically consented to receive calls from you. A prior business relationship does not override TPS registration unless you have fresh explicit consent from that individual to call them.
The 28-day rule flows directly from this. The register changes every day as new numbers are added. Running your wash once at the start of a three-month campaign and then dialling for the full period is not compliant. The ICO's guidance makes clear that the wash must be "dated within 28 days of the call being made". That is not a target or a best practice: it is the minimum standard.
The 28-day clock runs from the call date, not the campaign start date
If you are running a rolling outbound campaign, work backwards from your dial schedule. A batch of calls made on 15 June needs a wash dated no earlier than 18 May. Many operations wash weekly or monthly as a matter of course to keep this manageable.
There is one narrow exception. If the subscriber you are calling has given you specific prior consent to call them for the purposes of your campaign, TPS registration does not block you. The consent must be genuine (freely given, specific, informed, unambiguous) and must relate to your organisation, not a generic consent to "third-party marketing". In practice this exception is used for re-engagement campaigns to existing customers who ticked an explicit consent box at sign-up.
Who needs to run a TPS wash?
The simple answer is: any UK organisation that makes outbound live marketing calls to telephone numbers it cannot show have specifically consented to receive those calls. That covers most telemarketing operations, appointment-setting firms, financial services outreach teams, charity telephone fundraisers, and anyone running a bought telephone list.
There is a common misconception that TPS only applies to calls made by external call centres. It applies equally to in-house outbound sales teams. The obligation sits with the organisation that initiates the call, not the technology or the people making it.
Does TPS apply to B2B calls?
TPS covers personal telephone numbers: residential landlines, personal mobiles, and the direct lines of sole traders and most ordinary partnerships. A call to the main switchboard of a limited company or to a named director's direct corporate line is not covered by TPS. That is where the Corporate Telephone Preference Service (CTPS) takes over.
The complication for B2B marketers is that sole traders and small partnerships sit in a grey area. A plumber trading as "J. Smith Plumbing" is a sole trader: his personal mobile doubles as his business line, and if it is on TPS, calling it for marketing purposes is a PECR breach regardless of whether you intended the call as a B2B approach. See our detailed guide on TPS, MPS, and CTPS explained for the full breakdown of which register applies to which subscriber type.
As a rule of thumb: any B2B list containing self-employed individuals, small trading partnerships, or numbers sourced from consumer-facing databases should be washed against TPS before dialling. Limited companies, PLCs, and LLPs are CTPS territory.
Typical removal rates: B2C vs B2B
The UK TPS register is large. As of recent DMA figures, over 27 million numbers are registered, reflecting the fact that most UK consumers who have encountered unwanted calls have opted in to the register at some point. The registration rate has risen steadily since PECR came into force, and a consumer telephone list that has never been washed should be treated as significantly contaminated for marketing purposes.
| List type | Typical TPS removal rate | Main cause of removal | Notes |
|---|---|---|---|
| Consumer (B2C) telephone list | 30-45% | High consumer registration rate on residential and personal mobile numbers | Rate higher on older files; consent-sourced files already screened at source |
| B2B list (mixed SME/corporate) | 2-5% | Sole traders and small partnerships whose personal numbers hit on TPS | Corporate LTD/LLP numbers are CTPS not TPS; CTPS adds a further 1-2% suppression |
| B2B list (sole traders only) | 15-25% | Personal number = TPS-eligible; high registration among self-employed | Treat sole-trader-heavy sectors (tradespeople, freelancers) with care |
| Consumer file from a consent-based source | 5-15% | Individuals who consented but later registered with TPS | TPS registration post-consent overrides prior consent for non-specific marketers |
The 30-45% figure on raw consumer lists surprises clients who have not run telemarketing before. Buying 10,000 consumer telephone records does not mean 10,000 dialable numbers. After TPS suppression and further deduplication, a realistic dialable pool is often 5,500-6,500. Budget accordingly.
How the TPS wash works mechanically
There are two main routes for UK organisations to wash a list: direct access through the MPS/TPS portal, or via a licensed TPS processor (a bureau or data supplier that holds a TPS licence from the DMA).
Direct access via the MPS portal
Organisations that run regular telemarketing at scale can register directly with the Mailing Preference Service, which administers TPS access alongside the postal MPS register. The portal allows file upload, automated matching, and download of a flagged or suppressed output. Annual access fees vary by volume tier; for a mid-sized organisation making 50,000-200,000 calls a year, direct access is usually cost-effective.
Via a licensed TPS processor
Most list buyers and smaller telemarketing operations use a bureau or their data supplier to handle the wash. Licensed processors hold a valid TPS licence and perform the matching on your behalf. You supply the file, they return it clean. Many data suppliers (including our own service) incorporate TPS suppression into list delivery as standard, so the file you receive has already been washed on the date of supply. If you are not dialling within 28 days of that date, you will need a re-wash.
The wash workflow
| Step | Action | Who does it | Time |
|---|---|---|---|
| 1 | Format telephone file (one number per row, E.164 or UK local format) | Client / data team | Minutes to hours depending on file size |
| 2 | Upload to MPS portal or transmit to licensed processor | Client or bureau | Immediate upload; processing usually under 30 minutes |
| 3 | Register comparison run against current TPS register | MPS/processor | Automated; same day for most files |
| 4 | Receive suppressed output (matching numbers removed or flagged) | Client | Within hours of upload |
| 5 | Also wash against CTPS if any corporate numbers in file | Client or bureau | Separate process; same-day turnaround |
| 6 | Load clean file into dialler; note wash date for 28-day compliance tracking | Client / dialler manager | Immediate |
| 7 | Re-wash if campaign extends beyond 28 days from step 3 | Client or bureau | Repeat process |
What does a TPS wash cost?
Pricing from licensed processors in 2026 runs roughly £15-£60 per 1,000 numbers, with volume discounts kicking in above 50,000 records. Some bureaux charge a flat minimum (often £50-£150) per wash job regardless of record count, which makes small one-off washes disproportionately expensive. If you are buying a bought list with TPS suppression already applied, that cost is usually absorbed into the per-record list price rather than charged separately.
Direct MPS access has an annual licence fee rather than a per-wash charge. For organisations making calls continuously, the per-unit cost falls well below bureau rates at volume. The DMA publishes its current MPS licence fee schedule on its website.
In our experience, organisations that run telemarketing campaigns quarterly often find it more economical to use a bureau for occasional washes rather than maintaining a direct MPS licence. High-frequency outbound teams (daily or weekly calling programmes) benefit from direct access inside six months.
CTPS: the corporate equivalent
The Corporate Telephone Preference Service (CTPS) operates on the same legal basis as TPS under PECR, but covers corporate subscribers rather than individuals. A corporate entity (a limited company, LLP, or public body) can register its main switchboard and direct lines with CTPS, and organisations making unsolicited marketing calls must suppress against it before dialling.
CTPS registration rates are much lower than TPS: typically 3-8% of corporate numbers in a B2B list are registered. But the legal exposure is identical. Calling a CTPS-registered number without consent is a PECR breach just as calling a TPS number is. For a full treatment of how TPS and CTPS interact for B2B callers, see our guide on UK telemarketing TPS and CTPS rules.
What happens if you skip the TPS wash?
The ICO enforces PECR Regulation 21 under its civil monetary penalty powers. Fines can reach £500,000 for the most serious cases. Practically, enforcement actions have targeted organisations making hundreds of thousands of calls to TPS-registered numbers: a single accidental call rarely triggers a formal investigation. Systemic failure, or evidence that an organisation knew about the TPS requirement and ignored it, is where the ICO acts.
Beyond ICO fines, there are secondary consequences. Ofcom can take action against organisations generating excessive complaints, which can affect calling line presentation (CLI) status. Carriers can suspend outbound calling services for persistent nuisance callers. Reputational damage in regulated sectors (financial services, utilities) can be significant if a PECR breach is made public through an ICO enforcement notice.
The business case for washing is also straightforward even without the regulatory pressure. Calling someone who has registered with TPS because they dislike unsolicited calls is, almost by definition, a waste of a dialler second. Wash rates do not just measure compliance: they measure dial-list quality. A 35% TPS hit rate on a raw consumer file means 35% of your dialler time would have been spent generating complaints rather than conversations.
TPS wash is a PECR obligation; UK GDPR sits alongside it
Clearing TPS does not satisfy your UK GDPR obligations. For B2B calls you also need a lawful basis (usually legitimate interests, backed by a Legitimate Interests Assessment). For B2C calls you typically need consent. TPS suppression and UK GDPR lawful basis are separate requirements: you must satisfy both before dialling.