Two discounters on the Sunrise network, both of which lean heavily on promotions. That is exactly why the permanent price matters here: what do you pay once the promotion ends, not just in the first year?
Both providers advertise low entry prices, and for both the regular base price sits considerably higher. So always compare the permanent price, not the promotion. TalkTalk has a genuinely cheap base plan with no promo construction and scores better on customer satisfaction than yallo. yallo in turn offers the wider choice of roaming plans. If you take the promotion and switch afterwards, both work well, but if you keep the plan for years you should check the base price in the table above.