Honestly, my #1 recommendation on this is to get to know your businesses really, REALLY well. Business retention often isn't necessarily an issue of financial incentives, in fact in my experience that has rarely been the case because relocation carries with it a bunch of costs. It could be a wide variety of things prompting them to look elsewhere. Retention is all about the relationships and listening. For example, the issue may be that they need a new location to support new growth, but there is a lack of available space or developers doing build-to-suit for a new build. So it may not be them that you need to look at incentives, but instead some matchmaker work with the right developer and understanding what is happening in the market that might be preventing creation of a supply of the type of space needed. Another might need some type of capital incentive for retooling manufacturing. Another might be struggling to find the employees they need, or might be losing them due to housing costs or even employee spouses not being able to find appropriate employment. Another might be an owner looking to retire, and thus looking to sell the business which means you might want to think about a business succession program to help keep ownership local.
As a county, we do not offer incentives, in the traditional sense, for either retention or attraction. We are big on relationship building though regardless of whether it's a big Fortune 500 company with hundreds or thousands of employees locally or a small sole proprietorship and anything in between.
For bigger employers (and smaller ones as needed) we do a lot of that matchmaking and helping them navigate the state's workforce development programs that subsidize training and retraining and help with talent attraction. For retention of larger employers, especially manufacturers and R&D facilities, talent attraction is always one of the biggest obstacles so these workforce development programs usually prove very successful but the state does a horrible job at actually marketing them so a lot of employers don't even know they exist. One of the most popular is a program that allows employers to hire new workers to train in qualified apprenticeship programs but the state foots most of the bill.
We run our own Business Finance Corporation that backs bonds and offers SBA loans for qualified companies and also helps them find financing through other lenders when we cannot help them.
Finding available space for expansion is often an issue. One of our economic development reps has a commercial real estate background so we can offer some basic site selection services and then we have an approved list of commercial brokers that work with companies on a discounted rate if they are referred by us.
We have also set up a few "Roundtable" type groups around certain industries that we want to focus on retaining and expanding here where we sponsor monthly or quarterly meetings among representatives from those businesses where a) we hear about what issues they're currently facing and b) they get a chance to network with others in their industries locally. We've found these to be of varying success over the years but work really well if you can get one or two of the larger players in these industries locally to act as an champion or anchor for the roundtable group - it helps to add some cache to the working group and we get more buy-in from the smaller companies if it's not 100% government run. A lot of the businesses really like that these roundtable events are often a good way for them to also meet potential local suppliers or other vendors they might be able to work with.
Beyond matchmaking we also offer a lot of technical assistance, especially to smaller employers that might not have a lot of these type of resources at their disposal. A lot of the smaller retail and commercial businesses in our traditional downtowns often want to expand in place but occasionally run into problems with the expense of design for renovations or expansion especially in smaller, older, downtown storefronts so our Main Street group has a couple architects, designers, and historic preservation professionals on staff so we can provide some design services and then we have programs to help offset the costs of the actual renovations or facade improvements.
Similar to the matchmaking with the brokers, we also have a contract for professional services with some lawyers and accountants and marketing professionals that will work with very small companies to provide free work (up to so many hours).
There's a bunch more programs that I cannot think of off the type of my head but
the TLDR version is we do a lot of matchmaking and provide a lot of technical assistance. There are often a lot of programs at the state level beyond traditional tax incentives that employers just don't even know they exist, 90% of the battle in retention and expansion is pointing them in the right direction.
