Installer guide · 14 min read

B2B Cold Calling Rules in the UK: TPS, CTPS and PECR for Solar Installers

Short answer: you can cold call UK businesses without their consent, but not numbers registered with the TPS or the Corporate TPS (CTPS) unless that business has said it is happy to hear from you, and never anyone who has asked you to stop. Screen every list against both registers and your own do-not-call list, display your number, say who is calling and give contact details if asked. The rules come from PECR and are enforced by the ICO, which can now fine up to £17.5 million or 4% of global turnover.

A summary of the law and ICO guidance for solar installers, checked 30 October 2026. It is not legal advice.

Which laws apply to cold calling businesses

Phoning a business to offer a solar survey is direct marketing. Two sets of rules apply to it, both enforced by the Information Commissioner's Office:

If you offer finance on the call, FCA rules may apply as well: see offering finance on commercial solar. This guide is about calling businesses, not homeowners.

The rules for live marketing calls to businesses

Most marketing calls to businesses do not need consent. The ICO's guidance on live calls, based on regulation 21 of PECR, says you can make a live marketing call to a business number as long as:

• the number is not registered with the TPS or the CTPS, unless that business has told you it does not object to your calls;
• the business has not previously told you it does not want your calls;
• you say who is calling;
• you display your number, or a valid alternative contact number, and never withhold it; and
• you give a contact address or freephone number if you are asked for one.

Automated calls, where a recorded message plays, are different: the ICO says you must not make an automated marketing call unless the person has specifically consented to receive that type of call from you. For a commercial solar campaign, that means a person on the phone, every time.

TPS and CTPS: who registers where

There are two registers, and a B2B list usually contains numbers that belong on either. That is why the ICO says business callers should screen against both:

A farm run as a partnership, a sole-trader garage and a limited company warehouse can all be on the same solar call list, and they are not all on the same register. A business that has registered can still choose to hear from you: the rule is that you need it to have told you it does not object, not that you can never speak to it again.

The 28-day rule and how often to screen

The ICO says a number must be on the register for 28 days for the registration to take effect. Regulation 21(3) of PECR says a call is not a breach of the register rule if the number had been listed for less than 28 days on the day of the call. Read the other way round: once a number has been on the register for 28 days, calling it is a breach (unless that business has told you it does not object), however old your list is.

So a list screened once and worked for months goes out of date. Screen close to calling, and screen again before each new calling run, so a business that registered last month drops off before your caller dials it.

Bought-in data

If you buy or rent a call list, the ICO says you should make sure any TPS and CTPS screening the seller claims to have done happened recently, and that if you have any doubts about whether a list is lawful you should not use it. You are responsible for complying before you make the calls, whoever compiled the list.

The ICO's May 2026 penalty shows why. It fined Glasgow-based Energy Prices Direct Limited £160,000 for more than 700,000 unsolicited marketing calls between January 2024 and January 2025, made to individuals and businesses including numbers on the TPS and CTPS. The ICO said the company had bought calling data without establishing whether the numbers had been screened, and in some cases could not identify where the data came from. Building your own list from public sources avoids most of this: our commercial solar prospecting guide shows how to use Companies House, the EPC and DEC registers and Land Registry data. You still screen what you build.

Your own do-not-call list

The registers only cover people who have registered. Anyone, registered or not, can tell you they do not want your calls, and from then on you must not call them. The ICO says to keep a do-not-call or suppression list, to add a number to it rather than deleting every record of the business (otherwise it can creep back in with the next list), to screen against it as well as the registers, and not to make people take any action to confirm their objection.

Named contacts and UK GDPR

PECR covers the call. UK GDPR covers the personal data behind it. The ICO says information about a named person is personal data even when they are acting in a business capacity, and gives the example of holding a business contact's name and number on file. So if your list says "Jane Smith, Finance Director" with a direct dial, you need a lawful basis for using it, you must be open about where you got it, and people have an absolute right to object to direct marketing. If you do not know who you are calling, as with a main switchboard, the ICO says UK GDPR does not apply to that marketing, though PECR still does.

Using a telemarketing agency

Paying someone else to call does not pass the risk to them. The ICO says the organisation making the calls and the organisation instigating them must both comply, and that using someone else to make calls for you can make you both responsible. It says to check a third party is reliable and to have a written contract, which you must have if they use personal data for you. PECR also says you must not let others use your phone line to break the live call rules. Our guide to solar telemarketing lists the questions to ask an agency before you sign, including how and when it screens.

Fines and enforcement

The ICO enforces PECR. In its statement on the commencement of the Data (Use and Access) Act on 5 February 2026, the ICO said the Act gives it powers to fine up to £17.5 million or 4% of global turnover under PECR. Fines are not the only cost: an installer with a reputation for nuisance calls will struggle to book the meetings the calls were meant to produce.

What about email and LinkedIn?

Email follows different PECR rules. The ICO says the email marketing consent rule does not apply to corporate subscribers such as limited companies and LLPs, although you must not hide who you are and must give a valid address to opt out. Sole traders and some partnerships are treated like individuals and need to have consented, unless the soft opt-in applies. Our guide to cold email for commercial solar covers it in full, and LinkedIn lead generation for solar covers messaging on LinkedIn.

Compliance checklist for a solar calling campaign

With that in place, the cold calling scripts for commercial solar cover the opening, the five qualifying questions and the objections, and how to qualify commercial solar leads covers what to check before a survey goes in the diary.

Do it yourself vs have it done

If you have a caller with the time to screen, call, qualify and record objections properly, running your own calls can work. If not, TNW Marketing books pre-qualified, exclusive commercial solar site meetings with the decision-maker, using outbound calling, email, LinkedIn and paid ads, and is paid per qualified, attended appointment. See appointment setting for solar installers, how pay per appointment works, in-house vs outsourced lead generation and the UK solar lead providers compared, or hear from installers in our case studies.