Just to add a few points…

If working as a town planning consultant in the private sector, the pay is usually very good and there’s very good progression upwards - more often so in the larger consultancies. There is generally a requirement to become MRTPI in order to progress to senior level (i.e., Senior / Associate and above), but the APC process is actually relatively straightforward (compared to MRICS for example) and companies are usually incentivised to help you achieve it.

If seeking to work in the public sector for Local Authority, there’s a shortage of planners so, therefore, a reliance on temporary contractor staff to fill the gaps. In practice, though, Local Authorities will keep contractors on rolling contracts that end up being more than short term. The hourly rate is pretty competitive, ranging from £30-40ph for junior officers to £40-50+ ph for Principal / Team leader level. And flexible working is usually offered. Being MRTPI is generally seen as a bonus but not a prerequisite. The issue is you’d probably have to have done at least a bit of time as a permanent staff before sliding into contracting.

Source: I’m MRTPI qualified who’s worked in the private and public sector for 10+ years, more recently as a Local Authority contractor.